Romantic/sexual relationships between cousins (meaning, generally, first cousins) are a phenomenon that has been more accepted in some cultures and eras than others. A great many cultures today accept it, including a majority of the industrialized world.
Marrying one's extended relatives (which is technically known as clan endogamy) seems to have been common in human evolutionary history, since hominids usually lived in small nomadic bands with few available sexual partners. At the other end of the spectrum, much of the modern U.S.A. considers cousin marriage completely taboo, so Hilarity Ensues at the very mention of it. People from backwoods areas (especially the Appalachian Mountains) are often the preferred butt of many bad jokes as well as occasional bits of Self-Deprecation for the alleged prevalence of Kissing Cousins in their culture.
Despite the taboo, cousin marriages are legal in about half the states in the U.S.A., though not as much in the backwoods areas and more in the modern industrialized states, the opposite of what one might expect from hearing all those jokes. Legal or not, these marriages are still not very common due to the lingering cultural taboo. All states permit marriages between second and third cousins, but even these are looked at funny. In the UK, first cousin marriage is unusual and would be regarded as rather odd, but not with the same severity as the US. Second cousin marriages and beyond would be seen as unremarkable.
Expect some strong Values Dissonance between the media from the US and other countries, and between certain modern works and works from the nineteenth century and earlier, when the taboo was sometimes non-existent or even inverted. Full scholarly debate on why some cultures would forbid cousins, or even specific types of cousins, to marry, while others ignore or even encourage it, rages on, and lies beyond the scope of this wiki.
According to both Oxford's and Merriam-Webster's Dictionaries, the original definition of kissing cousins was simply a relative known well enough to be given a kiss in greeting, although this meaning has long since fallen by the wayside.
NOTE: This trope is for cases of actual relationships between cousins. Cousincestuous subtext goes in Incest Subtext.
- Angel Densetsu subverts this in a Flashback arc that details how Kitano's parents met. Midori is involved with her cousin and childhood friend, Chuji, who has a one-sided rivalry/obsession with Ryuichiro, and is most definitely Ax-Crazy. She insists that Chuji isn't evil, and asks Ryuichiro to defeat him in order to open his eyes. That really won't work, since he is evil now, and even considers Midori as just another easy girl. After he tells Ryuichiro this, Ryuichiro angrily lays him out in one attack, after being repeatedly struck with bronze knuckles and shrugging them off. Midori overhears and realizes the truth, culminating in the more heartwarming relationship between her and Ryuchiro.
- Axis Powers Hetalia: Austria is the cousin of Germany and Prussia, and he gets a lot of Homoerotic Subtext with them, though the Official Couple is Austria/Hungary. He allows Germany to practice sexual activities with him, to prepare Germany for Italy.
- In Ayashi no Ceres, Kagami claims that there's been a lot of this in the Mikage family line, although it's worth mentioning the context seriously calls his credibility into question: he's trying to provoke Ceres into emerging from his cousin Aya by coming on to her, taunting her with this claim, and attempting (or at least pretending to attempt) to rape her.
- In Black Butler, Ciel is engaged to his cousin, Elizabeth. They get along quite well, in fact Elizabeth is one of the few things that Ciel seems to care about.
- In Blade of the Immortal, Kagehisa Anotsu's true love is the swordswoman Makie Otonotachibana. Her grandmother was the younger sister of Anotsu's grandfather, which makes them second cousins.
- Bleach: Pure-blood Quincies are expected to accept endogamous Arranged Marriages to prevent contamination of bloodlines even if it means marrying cousins. The Ishida matriarch engaged her son Ryuuken to his cousin when they were both teenagers. Ryuuken and Masaki cared about each other as family but were reluctant to marry because they knew they were romantically ill-matched. Not only was Ryuuken not Masaki's type, he was also more attached to Kanae than he was allowed to be.
- When Nelvana Macekred Cardcaptor Sakura into Cardcaptors they made two of Sakura's classmates who were clearly fond of each other, with a snarky, cute relationship, into cousins. Whereas they removed the fact that Meiling and Syaoran were cousins by changing Meiling's surname to Rae. Tomoyo's crush on Sakura turns out to be this when it's revealed that they're second cousins. In a case of Generation Xerox, her mother also had a crush on Sakura's mother.
- A Certain Magical Index: In her brief appearance, Touma Kamijou's cousin Otohime Tatsugami tries to hit on him.
- Hanamori Pink did a short story called Cherry ♥ Blossom where the main couple are cousins. In fact, it's because they're cousins that they're able to save (the love lives of) their entire school by calling on the powers of their ancestors. It was published with other short manga in Japan, but the only official English translation is as an extra in the last volume of Mermaid Melody Pichi Pichi Pitch.
- It's been mentioned in a Code Geass Sound Episode that Suzaku Kururugi was engaged to his cousin Kaguya Sumeragi when they were children. Kaguya later decides that she is married to Zero, Suzaku's mortal enemy. What makes it particularly funny is that Suzaku eventually becomes Zero, though it's not known if Kaguya knows that.
- A Cruel God Reigns: William has a fling with his second cousin, and it is implied that Lilia may have cheated on Greg with her second cousin.
- Detective Conan:
- In one of the earlier cases, the killer's motive for killing his grandfather, etc. was because he fell in love with his cousin, and the older man forbid them from marrying. The killer's parents were also cousins, and the patriarch reluctantly agreed to their marriage.
- The series already hinted that Mary Sera may or may not be Elena Miyano's sister, but Word of God stated during an interview in Singapore that Shuuichi Akai and Akemi Miyano were indeed cousins. Whether they were aware of that fact isn't clear, but they were dating before the latter died.
- Elfen Lied has Yuuka and Kouta, complicated by a Love Triangle with a girl who alternates between homicidal and amnesiac. In the manga they end up together.
- In the manga of The Familiar of Zero the Prince of Albion, Wales, and the Princess of Tristian Henrietta are cousins who are in a secret affair (Long distance). Their love is cut short when Wales is killed.
- Masahiko and Shion from Family Compo are cousins and there's often a sense attraction between the two. The manga starts with Masahiko saying Shion is cute, before he learns she's his cousin. Oddly the series keeps on swaying between Masahiko being Sora's and Yukari's parent figures, and whether Shion and him are Like Brother and Sister or are true examples.
- In Fruits Basket the Sohma family is all cursed and they don't want "outsiders" to know about it, which means it's possible they have been inbreeding in order to keep it that way. They all address each other as cousins, but the family is so massive it's possible they're 3rd+ cousins so incest really isn't much of a problem. It's also never mentioned if their parents are related or not, it's just speculation.
- By a similar token, much the same happens in the manga Gakuen Heaven... except there, the cousin isn't the Designated Love Interest and doesn't factor into the series' Betty and Veronica equation at all.
- Makoto and Erio from Ground Control to Psychoelectric Girl have plenty of Ship Tease. It helps that Makoto didn't even know Erio existed until he was sixteen. Makoto also shows attraction to his aunt.
- Haiyore! Nyarko-san: Cuune wishes she and her cousin Cuuko were this. Cuuko has obsessions of her own.
- In ½ Prince, Rose kisses Prince in the game. Eventually, it's revealed that Rose's player is actually her cousin. And by cousin, it's meant that that she's her mother's older sister's husband's uncle's third daughter.
- In Hanasakeru Seishounen Rumaty and Kajika are unknowingly this. They do not actually get together in the end, but before Kajika and Lee Leng's Relationship Upgrade, the two are the closest out of all of Kajika's Love Interests. Bonus points for being each other's first kisses.
- The protagonist and his second-cousin in Hanayashiki no Juunintachi.
- Ayano and Kazuma from Kaze no Stigma are second cousins, with Ayano's father trying to pair them up.
- King's Game: Origin mentions that cousins Kazunari and Natsuko are in love. In contrast to most examples, they get scorn for their relationship. It's mentioned that cousin incest was legal but socially unacceptable in 1970s Japan.
- Koi to Utatane's plot is pretty much this. The protagonist is a high school guy named Kiichi, who has been in love for a long time with his older female cousin, Hana, who is also a teacher in his school. Due to work circumstances, Kiichi's parents has to move to Hokkaido, while he stays in Tokyo. His parents asked Hana to live with Kiichi while they're gone. Unsurprisingly, living with Hana only strengthens Kiichi's feeling for her. At first, Hana seems to oblivious to this and only look at Kiichi as a younger brother, but eventually Hana also starts developing feelings for him. In the end, Kiichi accidentally revealed his feeling to Hana. While at first shocked at this, Hana eventually return his feeling. In the epilogue, they are married.
- Crown Prince Kouen gets some Ship Tease with his first cousin Princess Hakuei in Magi: The Labyrinth of Magic. Their respective younger siblings seem to be well aware that there's something going on between the two. Although it's not considered unusual, since their culture is based on Ancient China.
- Suzuho in Magician's Academy is Takuto's cousin, and naturally one of the haremettes fighting for his affection.
- Shiratori Ryushi and Aoba Kozue, the Official Couple in the romantic-comedy Mahoraba, are second cousins.
- In Mai-Otome 0~S.ifr~, it is revealed that Sifr is the daughter of the King of Windbloom's brother, and it is strongly implied that she eventually marries the King's son, Bruce.
- Sachiko Ogasawara in Maria-sama ga Miteru is intending to marry her cousin Suguru after she graduates. It's an Arranged Marriage, and he's gay, but Sachiko has stated she has had feelings for him in the past.
- In Narutaru, Shouko Fukuyama has these feelings for her cousin Kyouji. Hell, she has it bad for him; she's about 13 years old and wants to bear his children. She has an It's All Junk hissy fit after being told off by his old crush Jyun. Eventually, Kyouji, who had been comatose for years, dies, and Shouko is all alone until she sees him after he turned into a... "Virgin Princess" and vows to keep on loving him.
- In the spin-off series Rock Lee's Springtime of Youth, Neji is implied to have more than just familial affection for Hinata, because there is a scene where he imagines the story of Romeo and Juliet, in which he casts himself as Romeo and Hinata as Juliet. In his fantasy, they're called Nejio and Hinaette and look at one another with sparkles in their eyes, before they run towards each other and embrace lovingly. In the same series, he gets so angry when he hears about Hinata trying to date Naruto, that he attacks Hinata in fury, and it's not just the big brother instinct anymore, but plain jealousy. Bear in mind that their fathers were identical twins, meaning that Neji and Hinata share 25% of their genes, as opposed to the 12.5% that would normally be the case for first cousins.
Neji: Never... you and Naruto... doing things like that it's... an infamy!
- There is also chapter 20, where Neji gets a severe nosebleed when he hears about Hinata's breasts getting even bigger than they already were.
- Lee's comments about how freakishly similar all the Hyuugas look to each other, even by family standards, might also be hinting at just how close the Hyuugas are.
- Neji also acts like a pervert towards the female characters in the Road To Ninja alternate universe movie, including Hinata. He acts like this especially towards Hinata.
- In canon, Neji remarked to his father that Hinata was beautiful when they first met. When he was 4 and she was 3.
- Karin showed some interest in Naruto at one point. Consider the fact that they're both from the Uzumaki clan. Her attraction to Sasuke is also this to a lesser degree, since the Uzumaki and Uchiha are genetically related, however distantly.
- The First Hokage, Hashirama Senju might do this when he married Mito Uzumaki, as the Uzumaki are an offshoot of the Senju. Such practice is not unusual; the two clans tend to trade marriage partners to maintain their ancestral connection. On top of that, the arrangement allowed Hashirama to keep an eye on Kurama, who was sealed within Mito. However, their exact relatedness is not stated.
- Then, of course, the final arc reveals that the Hyuga are related to the Senju, Uzumaki, and Uchiha. Naruto ends up marrying Hinata, the Hyuga princess par excellence. Though since their (known) most recent common ancestor lived hundreds of years ago, it doesn't pose much problem.
- In the spin-off series Rock Lee's Springtime of Youth, Neji is implied to have more than just familial affection for Hinata, because there is a scene where he imagines the story of Romeo and Juliet, in which he casts himself as Romeo and Hinata as Juliet. In his fantasy, they're called Nejio and Hinaette and look at one another with sparkles in their eyes, before they run towards each other and embrace lovingly. In the same series, he gets so angry when he hears about Hinata trying to date Naruto, that he attacks Hinata in fury, and it's not just the big brother instinct anymore, but plain jealousy. Bear in mind that their fathers were identical twins, meaning that Neji and Hinata share 25% of their genes, as opposed to the 12.5% that would normally be the case for first cousins.
- In Nerima Daikon Brothers, Hideki has a crush on his cousin Mako, who in turn is attracted to her cousin (and Hideki's brother) Ichiro.
- Mori and Honey from Ouran High School Host Club are first cousins, and quite close. It's probably just a case of True Companions, but Mori's bodyguard/protector-like relationship to Honey sure pleases the Yaoi Fangirls both In-Universe and out. Renge tries to encourage them to play it up a few times.
- Which one of the girls in Please Twins! is related to Maiku? In the manga, both of them. The one who isn't his sister turns out to be his cousin. They still get together, and if being cousins is an issue, they never say so.
- Rosario + Vampire: Tsukune Aono's cousin Kyouko becomes attracted to him when she sees how tough he has become.
- Amusingly when Sailor Moon S was Macekred in The '90s English dub, Cloveryway turned Haruka and Michiru into cousins to try and eliminate the lesbian content. But they didn't remove the subtext successfully, rendering them lesbian kissing cousins.
- In Sakura Diaries, the main character Touma's younger cousin, Urara, is constantly trying to sleep with him and keep him away from other women.
- In the Yuri Genre series Sakura Trick, the Beta Couple Kotone and Shizuku are cousins, and have The Big Damn Kiss and one point.
- Sand Chronicles's Fuji at one point dates his cousin Mariko, who takes care of him after moving to Tokyo. They eventually marry, but it takes a long time to gain his parents' approval.
- In a filler episode of Shugo Chara!, Amu admits that her cousin Shuu was her first real crush.
- In Super Dimension Fortress Macross/Robotech, Minmay and her cousin (no blood relation) Kaifun.
- Fumi from Sweet Blue Flowers has an unrequited crush on her cousin Chizu. She notes that, even if Chizu wasn't engaged, it wouldn't work out between them because they're cousins and because Chizu is a girl.
- It's worth mentioning too that Fumi and Chizu actually had a sexual relationship, with Chizu's engagement to a man signalling their break-up. It's later implied by Chizu to have not been so unrequited after all, as she cries to Fumi about how "We're girls...and cousins...so I can't be ''that'' kind of girl."
- Sword Art Online has a complicated case. Suguha Kirigaya wrestled with feelings for her older brother Kazuto, then when he became trapped in a VR game, her mother revealed that he was actually her cousin, adopted as an infant after his own family died in a traffic accident - him discovering that fact on his own led to him distancing himself from his adopted family. Suguha was overjoyed when Kazuto finally came out of his coma, less so when he revealed he'd found a girlfriend while stuck in the video game, and since Suguha knew that her feelings for him were unhealthy and unrequited, she tried to find a safer target for her affections, like this "Kirito" guy she met online one night in another VR game. Then Suguha found out Kirito and Kazuto were one and the same, meaning she'd fallen in love with her cousin twice over, which resulted in a brief Heroic BSoD.
- In Ten Yori Mo, Hoshi Yori Mo, Tadaomi's father and Mio's dead mother were siblings, so a Tadaomi/Mio match-up would be this. Tadaomi wants it badly to happen, but Mio does not.
- Katsuhito's first wife in the backstory of Tenchi Muyo! was his first cousin.
- In This Ugly Yet Beautiful World, Takeru Takemoto's cousin, Mari Nishino, is in love with him.
- In Tokyo Ghoul :Re, Kanae von Rosewald is obsessively in love with his cousin, Shuu Tsukiyama. While their family has a long history of Royal Inbreeding, Shuu seems oblivious to Kanae's feelings. This leads to Kanae becoming a Crazy Jealous Guy, repeatedly attempting to murder Kaneki out of jealousy.
- In Venus Versus Virus, Sumire's male cousin, Riku, likes her. He's several years younger than her, so it's unrequited.
- In The World is Still Beautiful, Kitra has feelings for his cousin Nike, but she only seems to him as a good childhood friend.
- Discussed by Eddie Izzard, in regards to the British royal family:
Eddie: She was one of our more frumpy queens. They're all frumpy, aren't they? Because it's a bad idea when cousins marry! [...] First rule of genetics: spread the genes apart, you know? But the royals are just obsessed with: "Are you a royal family? Are you a royal member? Well, then you can marry me, 'cause you're the same gene pool and our IQ's will go down the toilet." Fantastic. That's why there's no crazy royals, they're all kind of: [drawls] "Hello, hello. What do you do? Oh, you're a plumber. What on earth is that?"
- Among Jeff Foxworthy's indications that "You Might Be a Redneck..."
"If your family tree never forks..."
"If you go to family reunions hoping to pick up girls..."
- In the German comic Wendy, Wendy dates her foster-cousin for most of the story until her aunt decides that she doesn't want to adopt him and his twin sister after all, as they aren't as rich anymore. After that, he breaks up with Wendy to date his previous foster sister Vanessa instead, while implied to still live in her house. It's weird.
- Marvel superhero Black Bolt, the king of The Inhumans, is married to his cousin Medusa. Sorta justified: due to the limited gene pool of the Inhumans, just about every two-Inhuman marriage involves cousins.
- Mark Millar's post-apocalyptic Wolverine story "Old Man Logan" features a future were Hulk and cousin She-Hulk have bred and produced inbred offspring. This is all due to her being the only woman able to "Take the pace" of Hulk sexually. Hulk and She-Hulk are both radioactive too, which probably doesn't help... It's not the first time the romantic/sexuality thing has been brought up between these two as some of Fixit's dialogue with her implies he's more than game. There's also some implication that it may not be consensual.
- His future daughter engages in a literal example◊ in a Silver Age Elseworld story taking place in the future. (For those who don't know the Superman mythos, Lucy and Lois are sisters, which makes Lucy and Jimmy's son the cousin of Lois and Clark's daughter. Apparently, that doesn't bother Lola or Jimmy Jr, let alone their parents, happily watching them make out. The issue itself makes no mention of them being cousins, with the main obstacle to their happiness being It's Not You, It's My Enemies. They do live Happily Ever After in the end. As an Elseworld, it doesn't really count, but still how this got past the radar is a mystery.)
- The Man of Steel himself apparently had such feelings for his cousin Kara◊ (Supergirl). In that one, Kara tries to find Supes a girlfriend. After many failed attempts, we get the panel above, which seems to make it perfectly clear that the law is the only thing stopping them from pursuing a relationship (maybe they minded a lot less in the '60s?.) Eventually, Kara fixes Supes up with a girl that is nigh identical to herself, but older, and they hit it off. Unfortunately, it turns out yellow sun is her Kryptonite, and he can't leave Earth unprotected, so they must part.
- Also, from the same source as Lex Luthor stealing forty cakesnote comes Kara and Clark deserving a rest.◊ Maybe it's just hard to make her look unsexy, but... that looks far from innocent, and the repetition, though intended to drill the definition into a kid's mind, really makes it sound like she is saying "We deserve a rest, nudge nudge wink wink," and the big blue boy scout just isn't getting it yet.
- In Silver Age story Action Comics #260, Clark has Kara disguise herself as a superheroine from another dimension, and she and Supes proceed to have make-outs (in front of Lois), all to fool some dim alien invasion. She was explicitly underage at the time, too. Yeesh.
- And from Bronze Age storyline Krypton No More comes Superman walking out of the shower and finding his cousin waiting for him◊... and the writer seems completely unaware of the tone he is setting. At least Kara was already an adult woman at the time.
- In Supergirl: Candor, Kara is mind-controlled by evil telepath Saturn Queen into getting engaged to Ultraman, an evil Alternate Universe counterpart of Superman, but genetically it makes no difference.
- The ultimate desire of Marvel Comics superhero Namora has been shown to be her cousin Namor. Namor's late wife Dorma was also his cousin. And Namorita (daughter/clone of Namora, and therefore cousin of Namor) was in love with Namor at one point, though it was unrequited.
- MAD's Monroe was once visited by his punky Scottish cousin, and they made out a few times. She decided she didn't want to see him anymore because he was freaky with his "finger-skateboards", but as he said, at least he got to "make oot" that summer.
- In the X-Wing Series, Plourr Illo was engaged to her cousin since childhood. In the arc where she returns to her homeworld and takes up the reins, she's shown resisting the idea of marrying him, but since he shows a number of her traits—lots of courage, love of fighting and freedom, disdain for tradition for tradition's sake and even being a fighter pilot like her—she warms up to him. It's never shown whether they actually get married at some point. And their being cousins never seemed to bother Plourr, it was only the "arranged marriage to an aristocrat she hadn't seen in 20 years" part that was a problem.
- In the Douwe Dabbert story Florin the Loafer, count Justus van Bottericke attempts to force his cousin Gwendoline to marry him, because if she does not, he will lose the rights to his title.
- In Archie Comics' Sonic the Hedgehog, Knuckles the Echidna and his girlfriend Julie-Su are actually distant cousins, but neither one is aware of it, and it's not directly acknowledged anywhere in the series. They did, however, release a family tree at one point,◊ forgetting that their family tree closes back in on itself.
- Helene and Franz from a story by Wilhelm Busch. Despite him being a Catholic priest.
- Norman Drabble once ran into his girlfriend at a family wedding. After spending some time having fun with her, he asks why she's there. It turns out they're both related to the bride. A few strips later, it was revealed that they weren't blood relatives, but Norman didn't tell his girlfriend that immediately.
- Several of Madame D'Aulnoy's Fairy Tale couples are first cousins — a natural consequence of their both having to have Royal Blood and reflecting the royal families of their day. Such as Princess Belle-Etoile and The Bee and the Orange Tree. Also, Belle-Etoile and her husband Cheri are double first cousins—their fathers are brothers and their mothers are sisters.
- Also occasionally featured in the fairy tales of Henriette-Julie de Murat and Charlotte-Rose de Caumont La Force.
- In Murat's fairy tale Perfect Love, the main couple, Irolite and Parcin Parcinet, are first cousins. The two have another cousin, Azire, who is in love with Parcin Parcinet.
- Another Murat fairy tale, The Palace of Revenge, features first cousins Imis and Philax in love. Subverted, however, in that the two do not get married at the end.
- La Force's The Good Woman features two cousin couples. The main couple, Lirette and Finfin, are first cousins. The Beta Couple, Mirtis (Lirette's older sister) and Finfin's unnamed younger brother, are also first cousins.
- In the first written version of "Beauty and the Beast", Beauty and the Beast turn out to be double first cousins, their fathers being kings and brothers, and their mothers fairies and sisters.
- The French fairy tale The Little Green Frog features a second cousin couple, Prince Saphir and Princess Serpentine. Their fathers are first cousins.
- Rosanella features a second cousin couple. Rosanella's father and Mirliflor's father are first cousins.
- Prince Vivien and the Princess Placida has the titular Vivien and Placida, who are first cousins. Placida is the daughter of King Gridelin and Queen Santorina, while Vivien is the king's nephew.
- Also featured in the Breton fairy tale The Groac'h of the Isle of Lok. The protagonists, Houarn Pogamm and Bellah Postik, are first cousins through their mothers.
- Ourson by the Comtesse de Segur: the protagonist Ourson and his love interest Violette are first cousins.
- The now-forgotten French fairy tale novella The Tyranny of the Fairies Destroyed by Madame d'Auneuil features several couples. The main couple, Philonice and Anaxandre, are first cousins.
- In the Arabian Nights story The Story of Prince Ahmed and the Fairy Paribanou, the sultan's sons compete for the hand of their first cousin, Princess Nouronnihar. Ali, the middle son, ends up marrying her. Averted with the protagonist Ahmed (the sultan's youngest son) and his wife Paribanou, who are not relatives.
- In many Arab fairy tales, reflecting common practices, a woman is normally expected to marry her first cousin. (One example of such a couple is found in The Story of Dschemil and Dschemila, which comes from Libya.) This causes serious complications when she falls in love with another man; some tales have men forced to leave a tribe lest it happen. However, some first cousins graciously concede; this is often resolved by the new bridegroom offering the first cousin his own cousin.
- In the My Little Pony: Friendship Is Magic fanfiction, Maternal Instinct, the Changeling royal family, the House of Roachanov, has a reputation for practicing royal intermarriage, much like the European monarchies of old, ironic as the culture is predominantly of Imperial Japan. The Crown Princess, Pupa, is already set to marry her first cousin, Prince Morphin.
- The Phineas and Ferb fandom has a fairly large following for a pair of Original Characters named Marie Flynn (daughter of Phineas and Isabella) and Thomas Fletcher (son of Ferb and Vanessa), with the latter having a crush on the former. ("Isn't she your cousin?" "Step-cousin." Of course, even that falls apart in Alternate Universes where Phineas and Vanessa are half-siblings.) All in all though, Thomarie is pretty cute... even if Marie is as oblivious as her father.
- Ben 10 has a rather large following for Ben and Gwen since the first series. This can be connected to the Bleached Underpants history of the original draft of the show in which Ben and Gwen were not relatives but rather in the same school class.
- The Frozen fanfic Becoming Family has a romance developing between Elsa's daughter Katja and Anna's son Matteus. In their case, Katja is adopted so they're unrelated by blood.
- In Game of Thrones, cousin marriages are more commonplace among nobility in Westeros for political reasons. For example, in the show itself, Tywin and Joanna Lannister were first cousins and Ned Stark's parents were first cousins once removed. Among the fandom, there are fans who want Jon Snow and Sansa Stark to become an item and produce fanworks shipping them (known as the Jonsa ship for Jon/Sansa). Though Jon and Sansa believe they are half-siblings with the same father (Ned Stark), the Season 6 finale revealed to the viewers (and Bran Stark) that a long-believed fan theory of Jon's parentage is true: Jon is the son of Ned's sister Lyanna Stark and Rhaegar Targaryen, making Jon and Sansa cousins. Ned Stark claims and raises Jon as his illegitimate son alongside his kids with Catelyn to protect Jon from Robert Baratheon, who wanted to kill anyone with Targaryen blood.
- The pairing of Little Foot and Ali is surprisingly popular from the Land Before Time series in fanwork. However, Little Foot's grandpa clearly states that Ali's herd are Little Foot's family's cousins.
- Dancing With My Punchlines has Maedhros and Fingon (who are step-cousins but nonetheless), and Finrod and Curufin, and Finrod and Caranthir
- Superman story Superman of 2499: The Great Confrontation provides some examples:
- In Smallville fanfic Under the Influence, exposure to Red Kryptonite leads first cousins Clark and Kara to spend the night together.
- In No longer alone Narcissa mentions having sex with Sirius because she didn't want her first time to be with Lucius Malfoy.
- In The Berserkers Bride, Hiccup and Snotlout were originally meant to marry (Snotlout thinking that she was useless while she thought of him as The Bully), only for her to instead marry Dagur to unite their tribes. After she visits Berk with Dagur and reveals that she is pregnant, Snotlout tries coming on to her (thinking that she's now attractive) and even almost tries raping her.
- Pretty common in Harry Potter Next Gen Fics, because 12 of the 16 canon characters are Weasleys.
- This appears as Surprise Incest in The Ripple Effect. Jerrica's mother Jacqui grew up in the foster care system after her mother died in childbirth. At the end of the story Jerrica and her sister Kimber find papers that show who fathered Jacqui. It turns out that they share the same maternal grandfather as Eric Raymond. Jerrica had a crush on him when she was younger and Eric, during his Villainous Breakdown, developed a Villainous Crush on Jerrica and tried to rape her. Kimber and Jerrica are both grossed out by learning their relationship to their now deceased rival.
- The Lion King:
- In The Lion King, Fridge Logic dictates that Simba and Nala must be either cousins or half-siblings because Scar and Mufasa are the only adult male lions in the pride. This is later defied in The Lion Guard where it's shown that Nala's dad is a random, unknown lion.
- The sequel defies this by specifically mentioning twice that Scar is not Kovu's father, though fans still speculate. Kovu was meant to be Scar's son but then they noticed that'd make Kiara and Kovu cousins once removed.
- In Bambi, Faline is referred to as Bambi's cousin in some supplementary material. In the book they are first cousins through their mothers. Disney made sure to not mention this in the film, making it vague if they're related or not.
- Dames: Lovers Jimmy and Barbara are members of the same extended family. "It doesn't seem right loving each other the way we do, being related," says Barbara, only for Jimmy to parry that they're "13th cousins."
- The Secret Garden:
- In the 1993 film, Colin wants to marry his cousin Mary when they grow up so that they can always be together. Mary is amused but uninterested. Colin's response is a jealous loathing of Dickon, the servant boy who helps them in the titular garden, with whom he suspects Mary of falling in love. Their mothers are stated to be identical twins, thus making this even iffier genetically, since the offspring of identical twins are genetic half-siblings (assuming the other parents involved to not also be identicals, and to be two different people).
- In the 1987 Hallmark adaptation adult Colin (portrayed by a very young looking Colin Firth) proposes to Mary at the end and she accepts. However, in this version, they are not related — Colin's father is an old friend of Mary's parents instead of being Mary's uncle.
- In The Godfather Part III, Micheal's daughter, Mary, and his nephew, Vincent, are in love. Michael is against their relationship, but Mary's mother, Kay, is not. However, Michael's objections are apparently not based on consanguinity, but the danger of Vincent's lifestyle.
- In the Victorian farce The Wrong Box, Michael tries to resist his attraction to his cousin Julia:note
Michael: We both know what kissing leads to, and if I may be blunt, our children would be idiots.
Julia: Why, is there insanity in your family?
- In Cruel Intentions 2, the girls in the shower claim to be this (even though in real life they were played by real-life identical twins, making the scene an almost-crossover with Twin Threesome Fantasy).
- Dar and Kin in The Beastmaster. It's actually achieved through Fridge Logic; their relationship to each other is never noted at all in the film after the reveal that Dar is the son of Kin's uncle the King, and they don't see any problems in a romantic relationship by film's end.
- In Tombstone, Doc Holliday tells Wyatt Earp that as a teenager he fell in love with his first cousin; she entered a convent over their affair.
- In The Yards, Leo, the main character, had a relationship with his cousin Erica when they were younger. There is romantic subplot between the two throughout the movie.
- In Romy and Michele's High School Reunion, Michele lost her virginity to her cousin Barry.
- The main character in Barry Lyndon courted his cousin, which was a lot more common in that day.
- The 2009 film The Young Victoria is about the early life of Queen Victoria and her marriage to Prince Albert, her first cousin.
- In Mean Girls, Karen talks about what a good kisser her cousin is.
Karen: Yeah, but... he's my first cousin. Like, you have your cousins, and then you have your first cousins, and then you have your second cousins...
Gretchen: No, honey, uh-uh.
Karen: That's not right, is it?
Gretchen: That is so not right.
- The romance between Heather Mason and Vincent Cooper in Silent Hill: Revelation 3D. In the first Silent Hill film, Heather's biological mother Dahlia was the sister of the villain Christabella. In Revelation 3D, Vincent is the son of the villain Claudia, who is Christabella's sister. Therefore, Dahlia and Claudia are also probably also sisters and Heather and Vincent are probably cousins. It could be possible, however, that Dahlia and Claudia could be unrelated, if one was a maternal half-sibling (uterine) and the other was a paternal half-sibling (agnate/cosanguine). It's likely, however, that the writer of the second film missed the fact that Dahlia and Christabella were sisters in the first film. It's not the only Retcon.
- Brought up humorously by Daisy in The Great Gatsby when her cousin Nick asks her to visit him to reunite with Gatsby and when she arrives, she discovers his house is full of flowers courtesy of Gatsby. She murmurs he must be in love with her.
- In The Wolf of Wall Street to establish what a Cloudcuckoolander Donnie Azoff is, after Jordan Belfort and Azoff form a business partnership Belfort asks him if the rumors that he married his cousin are true. Azoff says they are (as noted in the Quotes page of this trope), and when Belfort asks about the risk of their kids having a disability, Azoff says they would drop them off at an institution to deal with kids like that.
- Averted in Once Upon a Time in China where Wong Fei Hung and his Aunt 13 are not blood relatives, though he calls her aunt even when they are around the same age because their fathers are sworn brothers.
- In the Saiorse Ronan movie How I Live Now, protagonist Daisy quickly falls in love with her cousin Edmond (they're first cousins, her dad is the brother of Edmond's mother) and the feeling is mutual. So much so that they eventually move beyond the kissing stage.
- Clerks: Jay says he'll have sex with Anything That Moves — including his own cousin, possibly.
- In The Blue Lagoon, Richard and Emmeline are cousins, traveling with Richard's father to San Francisco, where, presumably, she would have been raised as his sister. (Her parents had died, which is why they were traveling.) After the shipwreck, and the loss of the only adult with them, Paddy the ship's cook, things get a little more personal when puberty set in and they don't have anyone to explain it to them.
- German novel The Tin Drum has Agnes and Jan Bronski. It is left to speculation on whether main character Oskar is Jan's son or that of Agnes's husband Alfred. Agnes's second child is definitely from Jan and she kills herself because of realizing that.
- War and Peace has this combined with Not Blood Siblings. Sonya is attracted to her cousin Nikolai, who was raised as her brother. Natasha, who is at the time a child, assures her that they can still get married since Nikolai is only her second cousin. As young adults, Sonya and Nikolai get engaged, but Nikolai later breaks it off (with Sonya's consent) after he falls in love with Princess Marya. When they in turn get married, Sonya acts as an Honorary Aunt to their children.
- Jane Austen have examples of this.
- In Mansfield Park, the main character, Fanny Price, and her first cousin Edmund Bertram. (The elder Mr. Bertram was concerned about adopting Fanny for this very reason.)
- Anne Elliot in Persuasion is wooed by her cousin (and her older sister wants to marry that same cousin). It's implied that he's actually a few branches away on their family tree, but he still flirts with Anne by saying he hopes her name never changes.
- In Sense and Sensibility, Colonel Brandon's first love was his cousin Eliza Williams. They eloped, but his father stopped them and forced Eliza to marry Colonel Brandon's older brother. In the present, Eliza's namesake daughter (and Brandon's ward) is commonly believed to be Brandon's natural daughter.
- Pride and Prejudice:
- Mr. Collins is a cousin of some sort to the Bennet sisters, and comes to their house with the intention of marrying one of them.
- Lady Catherine de Bourgh wants her nephew to marry her daughter.
- The Camp Half-Blood Series and its associated spin-off series:
- Some couples in the franchise, particularly from the Greco-Roman series, are technically this, as their divine parents are part of a really complicated Tangled Family Tree. For example, the main couple, Percy and Annabeth, are first cousins once removed, since the former's father, Poseidon, is an uncle of the latter's mother, Athena. However, The Heroes of Olympus handwaves this by stating that gods don't have DNA, so it isn't creepy for couples with different divine parents to have a relationship. Couples with the same godly parents, however, is creepy.
- Other than gods, the Magnus Chase and the Gods of Asgard series has Sam being betrothed to Amir, who is explicitly stated to be a relative. They are both descended from the Real Life 10th-century traveler Ahmad ibn Fadlan, but whether there are closer shared ancestors is unknown. Cousin marriage (or at least marriage between close families) is actually a common practice in the Arab world, not only to strengthen alliances (the Arabs being traditionally a clannish society) but also to keep inheritance in-family.
- In Jade Green, Charles lusts for his cousin Judith, and is secretly planning on raping and killing her after she rejects her advances, much like the title character herself.
- In The Silmarillion by J. R. R. Tolkien:
- The Elf Maeglin was in love with his first cousin Idril Celebrindal, who is squicked by this, for "the Eldar wedded not with kin so near, nor ever before had any desired to do so." Also, Ar-Pharazôn, the last King of Númenor, married his first cousin, Tar-Míriel, against her will. It is claimed Numenorean laws prohibited any marriage closer then second cousins.
- Invoked with Maedhros and Fingon. To complicate things, they both were males — and their fathers were not unlike Cain and Abel.
- Aragorn and Arwen are first cousins several-times removed, as Arwen's uncle also happens to be an ancestor of Aragorn's many, many generations up the tree.note
- Galadriel and Celeborn are second cousins — Galadriel's maternal grandfather and Celeborn's paternal grandfather were brothers.
- Sam Gamgee and his wife Rosie Cotton are third cousins. Sam's great-grandmother Rowan was the older sister of Rosie's great-grandmother Rose.
- Merry Brandybuck's parents Saradoc and Esmeralda are second cousins. Saradoc's grandmother Mirabella and Esmeralda's grandfather Hildigrim were siblings (both children of Gerontius Took and Adamanta Chubb). Merry marries his third cousin Estella Bolger, who is the great-granddaughter of Hildibrand Took, another of Gerontius' and Adamanta's many children.
- Even besides the Not Blood Siblings romance in Wuthering Heights, there are, not coincidentally, two subsequent cousin-cousin relationships.
- In Felix Salten's Bambi, Bambi and Faline are cousins (their mothers are sisters). They start off a Childhood Friends, but come mating season as adults and Bambi becomes deeply attracted to his female cousin. They end up having twin foals together, but by their birth Bambi has already abandoned them.
- In the 1818 version of Frankenstein, Victor Frankenstein and his fiancée, Elizabeth Lavenza, are cousins who also happen to have been raised in the same household. In the 1831 version, Elizabeth was adopted rather than being related to Victor, but the two were still raised as siblings.
- A central part of the plot in One Hundred Years of Solitude is the fact that the founders of the Buendía clan were cousins, and therefore they feared the family would sooner or later breed monsters if they ever in-bred from that point on. Despite all efforts, it happens anyway.
- Louisa May Alcott's has two books with examples of this.
- In Rose in Bloom, the only people that the heroine Rose even considers marrying are three of her seven male cousins, Archie (who falls for Rose's lady-in-waiting Phebe), Charlie "the Handsome" and Mackenzie, aka Mac. Rose's guardian, Uncle Alec, explicitly says that he does not approve of cousins marrying, while her aunt Clara—overheard and tactlessly quoted by yet another cousin—holds that Rose should marry one of them "to keep the money in the family." After Charlie dies, Rose falls for Mac and marries him, while Archie and Phebe finally overcome the family veto to their relationship. As a bonus, Archie's 12-year-old brother Jamie gives Rose a love declaration at some point, which she rejects not because he's her cousin, but because she sees him as Justa Kid.
- In Jo's Boys, and How They Turned Out: A Sequel to "Little Men", Jo and Fritz's younger son, Teddy, mentions he wants a sweetheart like all his friends and that he asked cousin, Josie, first.
- In The Moonstone by Wilkie Collins, Rachel's has two suitors, both are her first cousins.
- In the Kushiel's Legacy series by Jacqueline Carey, distant royal cousins (his father is her great-grandfather's brother) Imriel and Sidonie fall for each other. Hard. However, their relatives (and the nation at large) aren't so much annoyed at the idea of relatives marrying so much as they are annoyed that Imriel's mother tried to take over the kingdom (twice, orchestrating an invasion the first time around) and at least some of the populace (mostly the ones still healing the scars from the invasion) thinks Imriel would do the same.
- Mercedes and Ferdinand in The Count of Monte Cristo.
- The protagonist of the novel Kung Fu High School is an example of this.
- In Rebecca the titular dead wife and her cousin, Jack Favell, were lovers. This relationship is presented to further underline Rebecca's depravity.
- The Wilkes and Hamilton families in Gone with the Wind have the tradition of cousins marrying each other. The text makes it clear that multi-generational inbreeding is the main reason for Melly's frail health and physique.
- The 1632 series has fun with this trope. The locals see nothing wrong with cousin marriage. The transplanted Americans are a lot more sensitive about this sort of thing (being from West Virginia, they've heard ALL the "inbred hillbilly" jokes).
- In Anne Rice's Lives of the Mayfair Witches trilogy, 13-year-old Mona Mayfair has a list of the male cousins she intends to sleep with and gets a considerable way down it before going on to other things.
- In the young adult book How I Live Now by Meg Rosoff, teenage cousins Daisy and Edmond fall passionately in love. Daisy wonders uneasily for a while "if that's the feeling your supposed to have when your cousin touches a perfectly innocent part of your anatomy that's even fully clothed". By the middle of the book, she doesn't care. The book treats their romance sympathetically.
- In Harry Potter:
- It's implied that purebloodism leads to frequent inbreeding. Arthur and Sirius explicitly state that all surviving pureblood wizards are related to some degree. Particularly after the wholesale slaughter of the second Death Eater war, there are simply so few purebloods left that those who still care about blood purity will have no alternative but to marry their cousins. Essentially if a pure or half-blood wizard marries someone who isn't Muggle-born, they're going to be related in some way — however distantly.
- Sirius and Regulus Black's parents, Orion and Walburga, were second cousins.
- Teddy Lupin and Victoire Weasley are fourth cousins once removed.
- Molly Prewett and Arthur Weasley were third cousins through the Black family even before they married.
- Harry and Ginny were strongly implied to be third cousins. The Black Family Tree includes as Dorea Black's husband Charlus Potter, whose information fit with him being James Potter's father, although this was jossed by the revelation in Pottermore of James's father as Fleamont Potter, whose exact relationship to Charlus remains unknown to date.
- After Tonks's Patronus takes a canine form, Harry wonders if she had been in love with Sirius, her cousin once removed, since he was an Animagus who turned into a dog. It turned out to be Lupin, a werewolf, however.
- The Gaunt family is described as "An ancient, in-bred, pure-blood wizarding family living in slovenly conditions in a shack in Little Hangleton." This is supposedly the main cause of poor Merope's "cross-eyed" appearance, and a streak of mental instability, such as with Morfin Gaunt. Although in this case, it's quite strongly implied that the Gaunts have gone much further than this trope to keep the bloodline "pure".
- The corrupt churchman Annias tries to persuade Queen Ehlana to marry her cousin, Prince Lycheas, in the David Eddings Elenium trilogy. She refuses, mostly on the grounds that she can't stand him but also on the grounds that he might actually be her half-brother, given that her father and his mother were a little closer than siblings ought to be. He isn't. Lycheas was actually the son of Annias, which was part of why he was pushing the marriage.
- In the King Arthur trilogy that begins with The Seeing Stone, the narrator is a medieval teenager (named Arthur) whose family circumstances parallel King Arthur's. He and his first cousin Grace are planning on a betrothal when they find out that Arthur's parents are really his foster parents and that he's actually the son of Grace's father by a peasant woman — so they're half-siblings, not cousins, and any thoughts of marriage have to be dismissed immediately. There's close and then there's too close.
- In Christopher Moore's Fool, Pocket has running on/off affairs with both Goneril and Regan, unaware that they're both his first cousins by way of rape. Probably wouldn't have stopped any of them if they did know, though. He certainly doesn't seem horrified by it when he does find out. In fact he winds up marrying the youngest sister Cordelia. Whether she knows about the family connection or not isn't revealed.
- Skinflick in Josh Bazell's Beat the Reaper is a young mafioso in love with his cousin. The narrator is non-judgmental about this.
- In Tanya Huff's The Enchantment Emporium Gales, a clan of witches usually (though not always) marry their cousins to keep from diluting the magic inherent in their genes and to keep said magic secret. Furthermore because there are far more more female Gales than male the boys usually "make the rounds" of their age group cousins before settling down. This imbalance between the sexes also leads to a lot of "close" relationships between the Gale girls. One of these, between main character Alysha and her cousin Charlie is particularly focused on in the book.
- In the novel Middlesex, the protagonist's parents were second cousins that eventually fell in love, but what they didn't know was that the father's parents were actually brother and sister, resulting in a rare recessive gene to make their child Calliope (later Cal) born intersexed.
- In Jude the Obscure by Thomas Hardy, Jude and his cousin Sue fall in love. It's the reason they resist their attraction in the first place which causes so many problems down the line. Though the novel attempts to make the argument that the judgments and restrictions of society are worse than the actions of the characters.
- An interesting twist is found in the Alfred, Lord Tennyson poem Lady Clare. The titular earl's daughter is engaged to her cousin, Lord Ronald, much to the delight of her nursemaid who promptly reveals that Clare is actually her own daughter, whom she substituted for the real Lady Clare, who died in infancy. Ronald, as the next male-line heir, ought to be inheriting everything that Clare's father left to her. Clare, horrified that Ronald would be "kept from his due" and married to a peasant, leaves the castle only to run into a bewildered Ronald. She explains everything, and he shrugs it off and says they'll marry anyway, "and you will still be Lady Clare."
- Tess of the d'Urbervilles is a rather tragic example. Tess' cousin Alec is obsessed with her and it leads to him raping and impregnating her, and her eventually murdering him. Though, as it turns out, his family merely took the d'Urbervilles name and they're not actually related at all.
- In The Tale of the Flopsy Bunnies Flopsy Rabbit is married to her cousin Benjamin Bunny.
- In The 39 Clues, all Cahills are distantly related...
- Owlsight has a brief relationship between Darian and (adoptive) double first cousin Summerdance.
- Illyria by Elizabeth Hand is about the romance between first cousins Maddy and Rogan, whose fathers are twins.
- In Nerve by Dick Francis, the protagonist is hopelessly in love with his cousin. She spends much of the story discouraging the idea, though it turns out the feeling is mutual, and she's beginning to come around toward the end.
- In the Nero Wolfe novel The Red Box, Nero deduces that one of the characters is interested in marrying his cousin. Ultimately, she is revealed as not actually being related.
- In Charmed Life, by Diana Wynne Jones, Cat and Gwendolen's parents were first cousins. Chrestomanci explains that when they decided to marry, it caused their family to make a great fuss. "It is, you see, rather a bad thing for cousins to marry when there's witchcraft in the family."
- In the Knight and Rogue Series Michael has a rather serious crush on Rosamund who is his second or third cousin (it never says the exact relation) and who, since they grew up together, sees him as a brother.
- Elric of Melnibone's betrothed is his cousin Cymoril. He damns himself (and ends up killing her) by accepting the demonic blade Stormbringer to rescue her from her brother Yyrkoon.
- First cousins Richard and Emmeline in Henry De Vere Stacpoole's The Blue Lagoon. Granted, there was a serious shortage of alternate partners
- Georgy and Oliver in Sorcery & Cecelia by Caroline Stevermer and Patricia C. Wrede.
- In the Babar books, the title character eventually married his cousin, Celeste. The Animated Adaptation changed this particular aspect, making the two unrelated and turning their relationship into Childhood Friend Romance instead.
- In the Montmaray Trilogy, both Sophie and her brother Toby are in love with their cousin, Simon. But neither of them knew he was their cousin when they fell in love with him, but both continue to engage in relations with him after finding out.
- Camille and Thérèse in Thérèse Raquin, though their marriage didn't involve much, if any, sexual activity.
- In the Bunduki novels by J.T. Edson, Bunduki and Dawn are adoptive cousins. They end up married.
- Being set in a Medieval European Fantasy world, this is prevalent in A Song of Ice and Fire. The most prominent example is Tywin Lannister, who married his cousin Joanna, and there are several other minor examples mentioned.
- Tywin and Joanna's daughter Cersei is also sleeping with her cousin Lancel (her cousin on Twyin's side, if you're curious). It becomes a plot point, thanks to how sensitive that information is—though not because he's her cousin, but because she's the king's widow, and how jealous her twincestuous brother is. Yeah, it kinda runs in their family... And, has done for centuries: there are two main lines of Lannisters, the ruling family based in Casterly Rock and the cadet, Lannisport branch in charge of the harbour, customs and navy. They criss-cross regularly. What? Do you really think the Rock could ever trust another House to run their trade hub?
- Ned Stark's parents Rickard and Lyarra were first cousins once removed, Lyarra being the daughter of Rickard's grandfather's brother.
- The Targaryens, due to their obsession with blood purity, would marry their parent's siblings or cousins if they did not have a sibling to marry. Viserys I married an Arryn cousin, who the current generation of Targaryens are descended from. Around the Dance of the Dragons, the Targaryen intermarriages with each other and their relatives the Velaryons makes for a very Tangled Family Tree (though maybe less inbred considering Rhaenyra's "Velaryon" children were more likely the result of an affair, though they all died without issue).
- Also, due to the fact that the Baratheons are descended from Aegon the Conqueror's bastard half-brother, the bride and groom in any Targaryen-Baratheon marriage will at the very least be distant cousins (one case was actually an aunt-nephew marriage, since the groom's grandmother remarried to a Baratheon and had a daughter). The same is true for any marriage between the Targaryens and Martells after the reign of Daeron II, due to Daeron marrying the Prince of Dorne's sister, while his sister married the Prince.
- Lord Wyman Manderly at one point suggests him or his second son Ser Wylis marrying his cousin Lady Donella Hornwood, hoping to get her lands.
- In In the Time of the Butterflies, Dede and Jaimito are cousins and her sister Maria Teresa has a brief Love Triangle between her two cousins, brothers Raul and Berto.
- In A Brother's Price, Jerin Whistler and the Princess Rennsellaer find, after downgrading his virginity status to technical levels, that they share great-great-grandmothers making them third cousins. Ren declares that it is distant enough for the relation to be fine and, indeed, that's how it's seen.
- One of Ren's sisters would rather marry Cullen Moorland, but his mothers were sisters to their father; they are seen as full cousins, and with birth defects and inbreeding being major concerns in this world, especially among the nobility with its fears of being polluted by common blood, she is voted out (her sisters do concede that Cullen would otherwise be a good husband).
- Eldest Porter is revealed to be the child of people who are genetically full cousins, but socially considered to be siblings. She's healthy—the onus is on her parents for breaking taboo like that. It should be noted that in this world men are very rare, and a man marries every sister in a family; the sisters themselves are born of several different mothers.
- In Isabel Allende's Eva Luna, when Rolf Carlé comes to America from post-World War II Austria, he lives with his uncle and aunt and is attracted to both of his cousins... not only his affections are reciprocated by both girls, but they actually jump him and they "share" the cousin/lover for their teenage years, until Rolf becomes an Intrepid Reporter and the girls marry local guys. The three still remember these escapades as some of their happiest moments ever. Also it's mentioned that the girls's parents did seriously consider to have him marry one of the girls, "sighing because there was only one if him".
- In the Lowlands Of Scotland series, Jamie McKie ends up married to both of his first cousins (not at the same time).
- In UK children's author Malcolm Saville's Lone Pine series, first cousins Jon and Penny Warrender are engaged by the end of the final book.
- In Andre Norton's Ice Crown, Nelis asks whether Roane is "ringed" to her first cousin Sandar, which causes Roane to laugh. Though at the end, he explains that he is the queen's first cousin, to show that their connection is not romantic.
- In The Darkangel Trilogy there's a love triangle in which all three participants are cousins. Two of them didn't know they were related at first, but the discovery has no effect at all on their romance either bad or good—it doesn't seem to be relevant to them.
- Gertrude Wentworth and Felix Young in Henry James' novel The Europeans.
- Seraphina: Staying true to the Western European feel of the setting, first cousins Prince Lucian and Princess Glisselda of Goredd are engaged.
- In Dorothy L. Sayers's Busman's Honeymoon, Lord Peter Wimsey worries about children because of how his brother's turned out. Harriet points out that his brother married his own cousin; his sister, who married a commoner, has children who are perfectly fine.
- In Un grito en las tinieblas; la vida de Zárate Arkham, the titular character sleeps with her cousin, although both of them were possessed by the spirits of their uncle and his female servant respectively—which make the sex scene a case of double incest.
- Rand al'Thor is worried about this when he considers courting the Andoran Daughter-Heir Elayne Trakand in The Wheel of Time after he learns that he is descended from Andoran royalty on his mother's side, making them distant cousins. He is reassured after an expert on genealogy informs him that if they were both commoners, they wouldn't be considered related.
- In Thai Literature Phra Apaimanee, Sin Samut and Arunratsamee are first cousin.
- In Making Money, marrying cousins is mentioned as traditional for the Lavishes in order to keep the money in the family, although "occasionally they married outsiders to avoid the whole 'three-thumbs' situation."
- Played with in The Hunger Games. The Capitol does not approve of Katniss' close friendship with Gale, seeing him as a potential rival to Peeta, so they claim the two are cousins. In the third book President Coin asks Katniss if she wants Gale declared as her new lover, which would make them this trope in the public's eye. Katniss declines.
- The Reynard Cycle: Two of the suggested brides for King Lionel are his cousins by his aunt. No one raises any objections over this.
- Anne de Bourgh and Colonel Fitzwilliam in the Mr. and Mrs. Darcy Mysteries.
- In Jorge Isaacs's María, the titular María is courted by her second cousin and narrator of the story, Efraín. The family doesn't necessarily approve, but it's less for their blood relation and more because Efraín is about to go study abroads and María is an Ill Girl who will not live for too long. It ends in tears when Efraín goes to study in London and María dies of her illness when he's still there.
- Agatha Christie's Tommy and Tuppence book, The Secret Adversary, features Julius Hersheimmer, a millionaire looking for his missing cousin Jane Finn. While he's never met her since his father disowned his sister (Julius' aunt and Jane's mother), he has her picture and falls in love with her. By the end of the book, Jane has been rescued and fallen for Julius in turn.
- The Kharkanas Trilogy:
- Hunn Raal's three cousins Serap, Risp and Sevegg seem devoted to him, and rumor has it that's because their loyalties are forged beneath the furs. They're second cousins, so it's legal, but still raises eyebrows.
- Averted with Faror Hend and Spinnock Durav. They're first cousins, and Faror Hend's attraction to Spinnock is so obvious even her commander has to tell her to restrain herself, while Spinnock is completely clueless.
- In Hope Leslie, there's William and Alice and, years later, Hope and Everell, but in both cases they are distant cousins.
- In The Dinosaur Lords, lovers Jaume and Melodía are first cousins, and no-one bats an eye at their romance, even pushing them towards engagement. Deliberate, as the story takes place in equivalent of fourteenth-century Europe.
- Averted in The Goblin Emperor: Maia, the new emperor, does not know much about the noble families, but when his marriage is discussed he draws attention to the fact that some of the potential brides must be related to him, and says that he would rather not marry a cousin. His secretary promptly excludes any woman closer than the third degree of kinship from the list.
- In Warrior Cats, seeing as they're semi-realistic cats, and they live in Clans that don't allow intermixing, this is kind of inevitable, and there are several such relationships like this.
- According to King Kelson getting a dispensation to marry a first cousin once removed isn't a problem, implying that the Church would be reluctant to allow marriage between a couple more closely related.
- In John C. Wright's Green Knight's Squire, when it comes up that Nerea is Gil's cousin, Ruff is quick to point out that means second cousin once removed.
- Wang Yuyan's one-sided crush on Murong Fu in Demi Gods And Semi Devils.
- In A Tangled Web by L. M. Montgomery, the Dark and Penhallow families have intermarried almost exclusively, to the point that during the time period the book takes place, pretty much all the marriages and relationships shown are between cousins.
- In Bright Lines Ella is attracted to her female cousin Charu. It's even more complicated becuse Ella was orphaned as a child and raised as Charu's sister. Charu strictly sees Ella as her older sister, bug Charu only sees Ella as a cousin.
- An episode of Just Shoot Me! involved Nina being pursued by a handsome man who, for some unfathomable reason, she has no attraction to. When he mentions he is also from Colby, Kansas, they discover they are cousins. He's completely disgusted and flees, while Nina is relieved that she hasn't stopped being attracted to men.
- Arrested Development had a recurring storyline about George-Michael's crush on his cousin Maeby who eventually turns out not to be his biological cousin). Furthermore, when these feelings become mutual, Maeby tries to hide from them by dating a boy from her school, who turns out to also be her cousin. Again, not by blood. This was mirrored in two storylines in the final season. The first saw Michael Bluth (played by Jason Bateman) thinking that a prostitute was his long-lost sister and hiring her to work at the company; she thought this was a Pretty Woman situation and started coming on to him. (The prostitute was played by Justine Bateman, who is Jason Bateman's real-life sister.) Then, in the final episode it was revealed that Lindsay was not actually Michael's biological sister. Upon finding out, she decided to act on a crush she had had for years. Additionally, Michael ended up going out with a woman who, unbeknownst to him, suffered from mental retardation as a result of her parents being cousins. It was a lot funnier and less creepy than this sounds.
- Relatively common in Hispanic Soap Operas. During Venezuelan soap Carita Pintada's pre-premiering the author claimed that the main couple could achieve a happy ending with a white wedding and all because they were only third or second cousins, coincidentally the closest blood relation allowed to marry according to actual laws. For the most (emphasis there) part in Latin America, people consider cousin relationships to be too incestuous only if they are first cousins; second cousins and onwards are not subject to this taboo.
- This is not uncommon in Soap Operas in general, given the frequency of "true parentage is revealed" storylines that can make previous non-relatives with crushes on each other into cousins. For example, Cassie DiMera and Shawn Brady on Days of Our Lives. Then there are people who skirt the edges of this trope by dating their half-siblings' cousins on the other side...
- Jonathan and Tammy were a popular couple on Guiding Light. However, the first time they slept together Tammy had no idea they were cousins and Jonathan was using her for revenge on his mother. When she did find out, she was angry at him for a long time. (About a couple weeks.)
- In the HBO series Dream On, Martin and his cousin (played by Helen "Supergirl" Slater) briefly undergo a bout of frustrated desire for each other, which only dies when they notice, when they finally get the time and privacy to indulge themselves, that their feet are too similar.
- On What Would You Do? (Nickelodeon), Marc Summers invited a teenage boy and a teenage girl to practice kissing.
Marc: Would you want to kiss her?
Boy: She's my cousin, why?
Marc: She's your cousin!? Are you cousins? I didn't know that! Wow! I have something I want to say but this will put us off the air!
- 30 Rock has this when Liz Lemon meets a guy that seems perfect for her. At least, until they go back to his place and she notices a picture of her great aunt. They do the math and figure they are third cousins (i.e. sharing a great-great-grandparent). There's a discussion on how closely related they could be without it being creepy. He says fifth cousins. She says never.
- Game of Thrones:
- In Season 2, while Jaime is captured by the Starks, Cersei ends up sleeping with her cousin Lancel because, according to the books, he physically resembles a young Jaime. While cousin relationships are not uncommon in Westeros, this establishes Cersei's disturbing habit of shaking the family tree for a bed partner.
- Also, like in the books, Tywin Lannister married his cousin Joanna, who died giving birth to Tyrion. The practical result is that her surname was already "Lannister" even before she married Tywin. In part, this also informs how much of a hypocrite Tywin is. He plans to force all three of his children to marry against their will to secure political alliances, demanding that they put the good of the family above their own personal happiness. Problem is, Tywin himself married for love marrying a first cousin meant he didn't secure a marriage alliance with another powerful Great House.
- Sansa's maternal aunt, Lysa Arryn tells her right after accusing her of sleeping with Littlefinger, that she can marry her son, Robin.
- Daenerys is actually Jon's biological aunt, but the two are the same age so when they get together it's similar to this. Things are further complicated by the fact that neither know about their blood relationship.
- That '70s Show had an early episode titled "Eric's Hot Cousin", where said tattle-tale Floridian cousin does not look like the last time she visited. She blatantly flirts, causing conflicted feelings in Eric. It turns out to be a trick to get him in trouble as revenge for the last time they butted heads.
Red: Eric, do I really have to tell you to stop staring at your cousin?
Eric: [snapping out of his male gaze] What?
Red: Stop staring at your cousin!
- In a 3rd Rock from the Sun episode, the aliens went to the family reunion of a family with the last name "Solomon", pretending to be long-lost relatives. Tommy fell in love with his "cousin" and Hilarity Ensued.
- Stephen Colbert's stalking of his ex-girlfriend Charlene (as in the hit song "Charlene (I'm Right Behind You)") had been a Running Gag for quite a while before it was revealed that they were also cousins. In his book, I Am America (And So Can You!), he says that it's okay to marry your cousin because The Bible doesn't say you can't.
- Colbert: Let's see... Leviticus Chapter 18 Verse 12—"Thou shall not uncover the nakedness of thy father's sister" ...blah blah blah... "thy mother's sister" ...yeech... "of thy father's brother" ...man, there were some sick Levites... "of thy daughter-in-law" ...fair enough... "of thy brother's wife." Nope! Nothing about cousins.
- Made mention of at least once in The Dukes of Hazzard:
Bo Duke: Daisy Duke, if you wasn't my cousin, I'd marry you!
Daisy Duke: Never stopped anybody in this family before.
- George dated his cousin in an episode of Seinfeld in an attempt to get his parents mad after they started neglecting him.
- On The George Lopez Show, Max gets a major crush on his attractive cousin. George made jokes about their mutant offspring (since Max by himself is already dyslexic) to discourage that. The cousin milks him for all he's worth by having him do all her chores.
- In The Big Bang Theory, Howard, while high from marijuana use (It Makes Sense in Context), admits he lost his virginity to his cousin at his uncle's funeral. This admission ends up coming back to bite him at the end of the episode in the form of a Mundane Ghost Story.
- Later, he is quick to point out that she was his second cousin.
- In the Gilmore Girls, Lorelai (and later Rory) is horrified to discover that her paternal grandparents were second cousins. Emily doesn't think it's a big deal, since that was common among upper class family in those days.
- The Nanny had an episode titled "Kissing Cousins" where Fran starts to date a Jewish doctor (played by Jon Stewart) who she thinks is perfect for her. They then meet up at a wedding in their temple, where Fran's mom declares, "Oh, I see you have met your cousin!" This makes them squick and they stop dating; however it is mentioned again in later episodes.
- In an episode of Friends, Ross and Monica's female cousin comes to visit for the wedding, and ends up staying at Ross' apartment. After a slow-motion Hair Flip, Ross finds he is attracted to her and decides that she is attracted to him too, leading him to try and make a move... Hilarity Ensues.
- In one episode of How I Met Your Mother, Ted, Barney and Robin go to a club. Barney grinds on a girl all night before she turns around and he realizes it's his cousin Leslie.
- In Chouriki Sentai Ohranger, Kaiser Buldont and Princess Multiwa wed in episode 41 and have a child near the end. It's okay because they're robots.
- In the Don't Trust the B---- in Apartment 23 season 2 episode "Original Bitch...", Mark tells June that he left a voicemail on her answering machine. June tells him she didn't get the voicemail because Chloe wouldn't give her the code. The conversation afterwards:
June: She [Chloe] won't tell me anything she cares about!
Mark: She might just a private person. I mean, I was like that when we first met.
June: The first day we worked together, you told me you boned down on your cousin 'cause you didn't want to go to college a virgin.
- Married... with Children: Everyone is family in Wanker County, which came as a surprise to Kelly. Apparently she was a little too "friendly" with one of her relatives; how friendly is unknown, but considering it's Kelly...
- The Frasier episode "Beware of Greeks" features a very one-sided version between Niles and Cousin Yvonne, who apparently makes a beeline for him whenever they're at a family gathering.
Frasier: A distant cousin who has a slight crush on Niles.
Niles: "A slight crush?" There are cannibals who are less man-hungry.
- The Tudors briefly covers the engagement between Mary Tudor and her cousin, Charles V of Spain.
- Night and Day's Tom Brake and Della Wells go much further than kissing, without realising at the time that they're biological cousins.
- On Downton Abbey, a major plot point is that the Earl of Grantham is without a direct heir, and so their very distant cousin Matthew is brought in as the only suitable candidate. It is hoped that the Earl's daughter Mary will become his future wife because their marrying would ensure that Mary could keep the house and fortune she would have inherited if she had been born a boy (especially since most of the money in the estate actually came from her American heiress mother, and it would be unfair for it to go to some distant relative of Lady Grantham's husband and bypass her daughter entirely). Nobody mentions that it's technically incest, and they eventually do fall in love. If you do the calculations, they're fourth cousins. Likewise Mary had been betrothed to the previous heir (before he died in the Titanic sinking), who was her second cousin. And it's implied her sister Edith had a thing for him, too.
- The next to last episode of Community takes place at Garrett's wedding. It isn't until the reception and Jeff's toast that it's discovered Garrett's great-aunt is his bride's grandmother.
Elroy: Now, this is a man that knows how to marry his cousin!
- Wayne and Daryl from Letterkenny try to avert this, though they mention coming close a few times.
- Frontier: During dinner Captain Chesterfield tells Grace that he used to lust after his cousin when she was betrothed to another man. His father marked him with a hot iron after finding out that he sneaked into her bedchambers one time.
- The second verse of Weird Al's Avril Lavigne parody "A Complicated Song" has the protagonist alone with his girlfriend for the first time, presumably about to engage in a little Angry White Boy Polka, when:
Who would have guessed
Her family crest
I'd suddenly spy
Tattooed on her thigh?
And son of a gun
It's just like the one on me...
- Second cousin, why are you so fine?
- Elvis Presley's song Kissing Cousins from the movie of the same name.
- Cousin Dupree by Steely Dan, where the title character hits on his sexy cousin Janine and promptly receives a thorough dressing-down for being creepy and incestuous... which doesn't bother him at all.
Well, we used to play since we were three / How about a kiss for your Cousin Dupree?
- Corb Lund's "Family Reunion" has a line that goes like this: "Cuz one of them I think I mighta dated back in school/ That's alright, in Alberta that's cool".
- Moosebutter has a pastiche of "On My Own" from Les Misérables called "Jon Boy Jon" about a redneck who is in love with his first cousin.
- The eponymous Brenda in "Brenda's Got a Baby" by Tupac Shakur got involved at the age of 12 with her 20-something cousin and conceived a child, and her parents were too wrapped up in themselves and their drug addictions to care. Her boyfriend/cousin leaves her sometime during the pregnancy, and everything goes to (even further) crap from there. Brenda is thrown out of the house by her mother shortly after she gives birth, and Brenda is ultimately driven to prostitution to support herself (now probably about 13 or 14) and her baby, and eventually killed, presumably by one of her clients.
- In Alfred Lord Tennyson's Locksley Hall, Amy, who loved and then left the narrator, is his cousin.
- The Bible:
Eat and drink and be merry tonight, for no man is more entitled to marry my daughter Sarah than you, brother. Besides, not even I have the right to give her to anyone but you, because you are my closest relative.
- In The Book of Tobit, it's not clear exactly how closely Tobias and Sarah are related, but their marriage is not only allowed but considered obligatory.
- Due to the nomadic, tribal lifestyles of the ancient Israelites, this is true throughout the Bible. Jacob married TWO of his cousins, the sisters Rachel and Leah, and also fathered children by their handmaidens.
- Also, because in the list of relatives and other people an Israelite man is not allowed to have sexual relations with, "cousin" is conspicuously absent.
- In Antigone, the eponymous character is engaged to her cousin Haemon. Haemon's father Creon and Antigone's mother Jocasta are brother and sister. It's worth mentioning that he is also her first cousin once removed since Antigone's father is a son of Jocasta's. Coming from that family, marrying a cousin must've seemed positively conservative.
- At the end of The Importance of Being Earnest, The Reveal that frees Jack/Ernest to marry Gwendolen also makes them first cousins. This isn't specifically addressed, but he does start referring to her mother as his aunt, so at least they're aware of it.
- In 1879, Cyrano and Roxanne from Cyrano de Bergerac are cousins. Although they don't actually end up together, their familial connection is never presented as squicky or an obstacle in their relationship. Given Catholic rules on consanguity this probably means 'cousin' was more a courtesy then genetic relationship.
- Alex and Jenny in Aspects of Love.
- Tybalt in Roméo et Juliette, de la Haine à l'Amour (though not the play it's based on) wishes this was the case with him and Juliet.
- In most productions anyway. In Hungary it's less "he wishes his cousin returned his romantic love for her" and more "he's so obsessed with her that he thinks all men, including himself, are unworthy of her". There's still some weirdness going on there, though.
- Toyed with in the anime. It seemed that Tybalt would become a Romantic False Lead for Juliet, but we soon see hat he's got no real romantic interest on her and settles on being her Big Brother Mentor instead. And Aloof Big Brother to Romeo, since in this version he double as Juliet's relative and as Lord Montague's Heroic Bastard. (His mother was a high-ranked Capulet lady, who was seduced by Laertes and later fell victim to Death by Childbirth).
- In Brighton Beach Memoirs, Eugene has somewhat of a crush on his cousin Nora. However, it's not romantic so much as that he's entering puberty and there's a beautiful girl in the house. His older brother Stanley has a similar attraction to her.
- Subverted in August: Osage County. Ivy is in a relationship with her cousin Little Charles, which is already considered pretty bad by the others. Then it's revealed that Little Charles is actually the biological son of Beverly, Ivy's father, making the two brother and sister as well.
- Monty and Phoebe in A Gentleman's Guide to Love and Murder. They're not too closely related though and they didn't meet until they were adults.
- Elisabeth: like in Real Life, Franz Joseph is expected to marry his cousin Helene, only to fall in love with Helene's sister Elisabeth. It's mentioned that they're cousins, but that isn't treated as the reason their marriage ended as badly as it did.
- As an extension for its love of the sibling version Fire Emblem has plenty of this:
- Several preexisting relationships in Fire Emblem: Genealogy of the Holy War's 2nd generation take on this form, and by selective pairing of characters in the first generation it is possible to make a vast number of such pairings. Two particularly noteworthy examples in the second generation are the predestined couples of Lana/Faval and Lester/Patty. Because their mothers Aideen and Briggid were identical twins, Intelligent Systems pulled off the impressive feat of doing this and BrotherSister Incest at the same time.
- It is possible to make Roy and Lilina from Fire Emblem: The Binding Blade cousins... by pairing Eliwood with the Pegasus Knight Fiora and Hector with either of Fiora's youngest sisters Florina or Farina in prequel Fire Emblem: The Blazing Blade. Since The Blazing Blade was not released yet at the time of The Binding Blade's own release (and the pairings involved exist among other possible pairings), the latter never makes any mention of this possibility.
- Fire Emblem Awakening uses a love system very similar to that of Genealogy of the Holy War. Either Lucina or a Chrom-fathered Cynthia or Kjelle can potentially marry their paternal cross-cousin Owain while other cousin pairings can be set up with certain combinations of parents. The international release has the status screens of such a pairing Bowdlerized to read "Companion" instead of husband/wife, though. A female Morgan mothered by Lissa or Emmeryn can also marry her cousin Inigo or Brady.
- Fire Emblem Fates allows the players to do something similar to to Fire Emblem Awakening, if they have the children of siblings marry. There are also two "set" pairs of cousins in the game, one of which can avert this or not, one of which plays it straight.
- The first set are Asugi, the son of the ninja Saizo, and Midori, the daughter of Saizo's younger brother Kaze. However, while they can reach an S-support, in the localization it ends with them as Just Friends, making them either an aversion or a straight example depending on the version itself.
- The second set are the Male Avatar and his Implied Love Interest Azura—their mothers Mikoto and Arete were sisters. The twist is they don't know they're cousins, and they don't find out until quite late in the Golden Path (and note, only the Golden Path, meaning in the other two they never find out). Even after they learn the truth, though, their S-support is explicitly romantic, making them the straight example. Of course, if they don't marry each other, it's possible for their respective children, who would be second cousins, to marry each other. And if the Avatar marries any of Azura's children, he/she'll end up marrying his/her first cousin once removed.
- It's also possible to pull off other couples like this depending on how the player pairs up the royal sisters. If Hinoka, Sakura, Camilla, or Elise marry any of the men who have daughters, the player can then hook these second-gen girls up with Shiro or Kiragi (for Hinoka and Sakura), or Siegbert or Forrest (for Camilla and Elise). For example, a Caeldori mothered by Hinoka is still perfectly capable of marrying her cousin Shiro.
- An ill-fated romance between two forms part of the plot of the adventure game The Dark Eye.
- Though nothing ever comes of it, Brother in Final Fantasy X-2 has a noticeable (and one-sided) crush on Yuna. Brother's father and Yuna's mother were siblings.
- It should be noted that in The Sims 2 and The Sims 3, the game does not even allow the option for first cousins to be married. (A certain cheat will allow them to have offspring, if the player so chooses). However, more distantly related Sims have the ability to seek romantic interactions with one another (probably because the family tree in the game does not recognize first cousins once removed and beyond, or great-grandparents for that matter).
- At the end of Persona 4, The Protagonist's little cousin Nanako tells him that she wants to marry him when she grows up, and apparently won't take "no" for an answer. If the player didn't max the link, her father won't allow it. If it's done, Doujima's gonna hold the Protagonist to it.
- In Bully, the Preppies are the kids of a bunch of inbred rich people. When Gary gets them to attack you with his old trick of insulting them and saying you did it, the "inbred" insult is met with indignation and the phrase "And first cousins is legal anyway!"
- In Jade Empire, it's revealed that Dawn Star is the long-lost daughter of Sun Li, the brother of the Emperor. As a result, if a male protagonist forms a ménage à trois with the Princess Silk Fox and Dawn Star, the two ladies are in this kind of relationship.
- In Matches and Matrimony, this is one of the nine paths which the player character can take, if she accepts (or is too weak-willed to refuse) the proposal of her cousin Mr. Collins.
- BlazBlue: While there are no examples given, the Yayoi family (Tsubaki's family) practices this; they are so obsessed with blood purity that marrying in the family is the only choice they get. Which has led to the family being Royally Screwed Up; Tsu's the only surviving heir to the family.
- Dorian Pavus and a human Inquisitor in Dragon Age: Inquisition are distantly related. Dorian brings this up at one point, and if a male Inquisitor is engaged in a romance with him he has the option of asking whether it's okay to continue flirting or not. Dorian's fine with it, as it's very distant (three whole Ages, if he's being literal).
- Crawford Starrick and Pearl Attaway are cousins as well as business partners and members of the Templar Order in Assassin's Creed: Syndicate. Dialogue between them indicates they have a long history together; having apparently been childhood sweethearts, Crawford once asked Pearl to marry him and was deeply disappointed when she refused his proposal, as well as being clearly grief-stricken after she is assassinated by Jacob Frye (as one of his minions unfortunately learns).
- Generally unavoidable in Crusader Kings if you want to keep a marriage alliance alive for more than one generation.
- Bart and Margie of Xenogears are first cousins and engaged for various political/dynastic reasons. Although Bart rescues her from kidnappers at one point and they do have genuine affection for each other, neither one seems to be very enthusiastic about the prospect of marriage.
- A lot of visual novels will often feature a cousin as an option. Whether or not the main character ends up in a relationship with her (or him) depends on the player's choices.
- One of the routes in the Aoi Shiro pairs the main character up with her cousin Kaya. Demon Vampire Lesbian Kissing Cousins?
- Saki from Snow Sakura is a slight deconstruction. She and her cousin Yuugi fall in love but their school's vice-principle decides to butt in because their relationship isn't socially accepted. This causes drama as the two are forced to be apart. It helps that the vice-principle is depicted as a Jerk Ass strawman while the pairing is supported by an American teacher and their parents.
- Sono Hanabira Ni Kuchizuke Wo: Sara and Kaede; they (at time of writing) supply the Trope Image for Yuri Genre.
- Miyuki Takamachi of Triangle Heart 3: Sweet Songs Forever. Both her status as Kyouya's cousin and potential love interest may or may not still be present in Magical Girl Lyrical Nanoha, as one shot in the first season showed signs of her getting jealous when she heard that Kyouya was going to visit his girlfriend, Shinobu.
- The entire Nanaya clan from Tsukihime, with the exception of Shiki due to his situation. They only breed within the clan to sustain and increase the psychic power within their bloodline.
- While he's joking for the most part, Umineko: When They Cry's Battler Ushiromiya is not adverse to playing grab-ass with his first cousin Jessica. As for more serious cousin-cousin relationships, the second half of the story reveals that Sayo Yasuda (who is implied and later confirmed to be Shannon, Kanon, and Beatrice) is involved with as many as three of his/her cousins. Who are also his/her niece/nephews (since Kinzō is both Sayo's father and grandfather). As it turns out, this is a large part of Sayo's issues, since finding out that s/he's actually related to his/her love interests makes him/her think of him/herself as disgusting and no better than Kinzo.
- Sayaka from Yoake Mae Yori Ruriiro Na, although the protagonist treats her like and refers to her as his sister.
- Calvin of Charlie Horse provides a handy chart.
- Referred to in Dead Days. Brown-hair claimed he knew everything, so Blondie tested him out. Brown then stated Blondie's first kiss was with a cousin at a family reunion. His name was Steve.
- Tedd of El Goonish Shive averts this trope, being almost allergic to the idea of his "ugly cousin" Nanase as a sexual being at all. (Said cousin is, of course, scorchingly hot actually, as Tedd admits much later.)
- Rudy and Fiona in Kevin & Kell are technically first cousins, but only by marriage (two marriages actually) and through Fiona's stepparents both times, so it's okay.
- The webcomic Lines and Stripes has a couple like this, but the objection of people isn't so much that they're cousins, but that they're double cousins. The other wiki has an explanation as to why this is a bad idea.
- In Templar Arizona, Mose's grandfather wants him to "keep the bloodline pure" and tries to browbeat him into taking up with the temple dancers. Mose objects on the grounds that they're his cousins ... and underage.
- Trigger Star: Sauerkraut and Avocado's idol, Exlax The Mighty. Not only are they cousins, they were lovers.
- In Scandinavia and the World, Norway and his cousin, Jan Mayen, actually get in trouble for being in a relationship, resulting in the latter's execution.
- Sandra on the Rocks: Eloise has a romantic thing for her cousin — perfectly legal in France, where they live, but close enough to make her uncomfortable about declaring it. On the other hand, when Nadine teases her about the subject, it gives her an excuse to declare that "FORBIDDEN LOVE IS HOT!!!"
- Spoofed in Hark! A Vagrant: Edward the Black Prince wishes to marry his cousin, but is unable to because he needs to make an advantageous marriage. His father, Edward III, notes that it's natural to want to marry one's cousin but the realm comes first.
Edward III: God, the cousins I could have, but no...
- HomeSchooled: Juan the gardener has an infatuation with Dulce the housekeeper, despite the fact that they're 2nd cousins. This disgusts her to no end.
- Of course, considering the fact that EpicRapBattlesOfHistory also has real-life historical figures as some of their many characters, there's bound to be at least a few lines about them having a relationship with their cousin.
- On The Angry Beavers, the episode "Stump's Family Reunion" has Dagget trying to help Stump hook up with his distant cousin Vanity. Norbert was there too, and intended to help (because he thought Dagget would screw up), but his help is spotty as he had an ear infection and acted goofier than his brother usually did.
- When Hervé and Nicolas follow the gang to the factory in an episode of Code Lyoko, Odd and Aelita pretend to have sneaked out of school on a date, despite the fact that Aelita joined the school under the pretense of being Odd's first cousin. Note that it works as a perfect in-universe Fridge Brilliance: it was Fake-Out Make-Out, but Hervé and Nicolas probably reads it: "They are kissing? But... They are cousins! Oh... No wonder they are hiding." Notably, when Hervé report the fact to Sissi, she obviously doesn't believe him and finds the concept absurd.
- On King of the Hill, Bill goes back to his ancestral home and meets three beautiful women named Lily, Rose and Violetta. All three come onto him, but Bill knows that one of them is his biological cousin while the others are his cousins' widows; he just doesn't know which is which. The three all sneak into his room at night and wind up in a cat-fight before Bill's other cousin (an almost-certainly-gay male) tells Bill it's Violetta he's related to. Bill winds up sleeping with both Lily and Rose.
- In Monster Buster Club, Cathy's big secret is that she kissed her cousin Elton, but only on the cheek, and only on a dare.
- On Oggy and the Cockroaches, Jack, Oggy's cousin, is attracted (and has the feeling reciprocated) to Monica, Oggy's twin sister. One episode has them married with an infant daughter.
- Scooby-Doo and his cousin Scooby-Dum were attracted to one of their cousins, Scooby-Dee. It's less Squicky since they're dogs, and inbreeding is common.
- The Simpsons:
- Apparently the motivation for the founding of Shelbyville was a disagreement between Jebediah Springfield and Shelbyville Manhattan over whether to legalize cousin marriage. At one point Bart escapes a bunch of Shelbyville kids by pointing and shouting "Look! Somebody's attractive cousin!"
- Luann, Kirk and Milhouse all look so similar that Bart once asked Luann and Kirk if they are siblings. In the season 26 episode "Let's Go Fly a Coot", Milhouse tells Bart that his parents are actually cousins. They were born in Shelbyville and this follows Shelbyville custom, as the town was founded by early dissenting Springfielders who wanted to inbreed.
- The Simpsons Uncensored Family Album has Homer Simpson's detailed family tree depicting second cousins Amos Graycomb and Moselle Stemple marrying and having four children together.
- In the Swedish/British cartoon The Three Friends and Jerry all the main characters are after blonde, very developed Linda, even her cousin Frank. Especially her cousin Frank.
- Invoked in an episode of Totally Spies!. When looking up her relatives in France, Alex wonders what her cousins look like and pictures a handsome guy with Bishie Sparkle.
- Wolverine and the X-Men made Silver Samurai and Mariko Yashida into husband and wife, even though they're cousins in the comics. It's not mentioned one way or another if they're still related in the cartoon. Justified as they're Japanese and it fits their culture.
- In the "Whittle Me This" episode of The Fairly Oddparents, Timmy mentions that hillbillies are cool due to several reasons, including that they can take their cousins to the prom.
Alternative Title(s): Cousincest