A very simple Love Trope. Bob falls in love with Alice, but Alice does not reciprocate. Bob eventually marries her sister Carol.
Look out for when this overlaps with Double In-Law Marriage.
This can entail a Betty and Veronica situation, where a quiet Betty whom he would never have noticed in the ordinary run of things comes to his attention when his prolonged wooing of Veronica means he sees a lot of her and so comes to notice her profound but not paraded virtues. Similarly, any other pair of contrasting siblings where one is immediately attractive, but either has hidden flaws, or is just not interested, and the other has Hidden Depths (such as a Miles Gloriosus and The So-Called Coward) can produce this trope.
Or a situation where Bob and Carol are the same age, Alice much older, and Bob's interest is a Precocious Crush while Carol is still immature; growing up makes Carol mature and Bob notice her.
May overlap with Give the Baby a Father, especially in historical settings; marrying the woman pregnant with your brother's child not only protects her from the scandal but makes the child legally part of the family.
See also Does He Have a Brother? and Doppelgänger Replacement Love Interest. Love Father, Love Son is similar, but with a generational difference. If the timing of when feelings change isn't ideal, look out for the Sibling Triangle.
- From the 'Blunt Grandpa' Oscar Meyer commercial:
Grandson: How did you know Grandma was the one?Blunt Grandpa: When her sister dumped me.
- Occurs in D.N.Angel, where Daisuke ends up falling love with Riku, his initial Love Interest (Risa) 's sister.
- Anatolia Story: Himuro, Yuri's boyfriend from the 20th century, ended up marrying her younger sister Eimi.
- Fullmetal Alchemist: Token Mini-Moe / Little Miss Badass May Chang is smitten with Edward Elric... until she actually meets him. She soon falls in love with Alphonse instead.
- Given a lampshade in Ashita no Nadja. A girl named Marianne is in love with a boy named Francis, who's in a Sibling Triangle since he and his twin brother Keith both love main heroine Nadja (who leans more towards Francis, but once was VERY strongly leaning towards Keith). Therefore, she believes that Nadja should go with Keith, which would not only help Keith but would help her to get Francis's affections. She is so convinced of such a possibility that she even tells such things to Nadja herself.
- Suzuna Ayuzawa, the younger sister of the title character in Maid-Sama!, is actively trying to invoke this on Shintani Hinata, a Hopeless Suitor for her sister and their mutual Childhood Friend. She succeeds.
- A variation in A Bride's Story occurs with a woman named Talas. In her culture, it is customary to marry your husband's brother if he dies before having children. Her first husband had four brothers, and each married her and died childless in succession until each one met an untimely end. Talas had to Settle for Sibling four times in a row.
- Riku from Wandering Son falls for Shuuichi Nitori despite Shu's older sister Maho liking him, and Shu not returning the feelings. After a while Riku falls for Maho properly and they begin dating.
- Attempted in FLCL, when it's shown that Mamimi's behavior to Naota comes from her being totally broken after his brother Tasuku left to the USA. Towards the end, however, she thinks better of it.
- Buffy Season 8—Xander, who had had a crush on Buffy way back in season one, winds up dating Dawn (who likewise had a crush on him back when she was a teenager in season five). Made even more awkward because this was right when Buffy realized that she might have feelings for him herself.
- In Astro City, Silver Agent's first girlfriend got over him and married his brother.
- In X-Men, Scott's ex-wife Madelyne Pryor dates his brother Alex for a while.(Naturally this includes a period where she was crazy/possessed and convinced him to help her destroy the world while both wore Stripperific outfits.) Interestingly, in the Mutant X universe Madelyn never met Scott (who disappeared with their parents and is presumed dead), and she and Alex wound up married (though not necessarily happily).
- Inverted in Nexus as Dante tries to get June to settle for him after his brother disappears.
- Kaworu ends up taking this route in Nobody Dies, since Rei is... emphatically not into him (as demonstrated by a gruesome Noodle Incident involving "loss of ocular virginity" when he tried to press his suit too hard) but her marginally saner sister Kei is. It tells you something about Kaworu that it took Kei to point out that she is literally physically identical to her sibling (they're clones) for him to even realise this might be an option.
- Trusting In Faith: Glinda can't have Elphaba so she finds comfort in her younger sister. This element of their relationship makes Nessarose insecure as she feels like a Replacement Goldfish.
- Word of God says that The Book of Life's Xibalba originally courted La Muerte's twin sister, La Noche. She, in turn, married his brother El Chamuco, who used to court La Muerte and still has feelings for her. Confused?
- In The Princess and the Frog, when Charlotte le Boeuf can't get married to Naveen to fulfill her dream of marrying a prince, she (at least jokingly) toys with the idea of marrying Naveen's brother instead. He's six-and-a-half.
- In Prince Valiant (1954), Sir Gawain hooks up with Princess Aleta's sister Ilene after Aleta ditches him for Val.
- Played with in The Frisco Kid; the rabbi protagonist is arranged to be married to the daughter of a local Jewish merchant, without having met her; she's vain, selfish, a total flirt and obviously not a good match for him. Her shyer, more modest and withdrawn sister is a much better match... as the rabbi discovers when he eventually arrives in town, takes one glimpse of the younger sister and falls hopelessly in love with her, without having even met his intended bride. He ends up marrying her instead.
- Happens at the beginning and end of The Palm Beach Story, though we don't understand that it happened at the beginning until the end.
- The opening credits play out over a bizarre, dialogue-free sequence in which the bride and groom, Gerry and Tom, seem to be in two contradictory situations at once. We later learn that Gerry and Tom are both one of a pair of identical twins, and Gerry's sister was engaged to Tom's brother. However, Gerry also loved Tom's brother and decided to take her sister's place at the altar... not knowing that Tom had taken his brother's place at the altar so he could marry Gerry's sister. So even though Gerry and Tom weren't initially in love with each other, they both settle for the siblings of the people they really loved.
- After five years of marriage, Gerry decides Tom would be better off without her, and plans to divorce him and marry a rich man who can bankroll Tom's business idea. She meets such a man on a train to Palm Beach, John D. Hackensacker III. As they haven't formally divorced yet, Tom pursues Gerry to win her back, but she forces him to go along with her scheme, leaving the door open for Hackensacker's sister, the Princess Centimillia, to pursue him. When Tom and Gerry decide not to divorce after all, they reveal to the ecstatic Hackensacker siblings that they each have identical twin siblings. In the final scene, Tom's very confused-looking brother is marrying the Princess and Gerry's equally confused-looking sister is marrying John.
- Something like this happens in Like Water for Chocolate. Basic outline: Boy Meets Girl. Boy likes girl; girl likes boy. Girl can't marry because of cultural tradition. Boy can't be around her alone because of a restrictive culture. Boy marries girl's sister to be close to girl.
- A variant at the end of Night at the Museum: Battle of the Smithsonian. Larry appears to be starting a relationship with a woman who strongly resembles Amelia Earhart. At one point, he asks if she's related to her.
- In Psycho II we learn that Marion's sister Lila married her boyfriend Sam. Lila's resemblance to Marion may have made her a Replacement Goldfish as well.
- The Patriot: Benjamin Martin is a widower with seven children at the start, but he's on good terms with his sister-in-law and visits her with his family from time to time, who becomes a sort of surrogate mother for her nephews and nieces. They eventually get married by the end of the war.
- In A Brother's Price, due to male Gender Rarity Value, all the sisters of a family marry one man, so a man cannot settle for sibling, he gets all of them or none. However, a family who offers for Jerin seems inexplicably (it is suggested) unwilling to consider one of his (not yet of age) brothers, or any of his (close to him in age) cousins, despite it being an arranged marriage, anyway. (Though they do appreciate Jerin's good looks) A minor character, who would like to get his sisters married to a brother of his wives, for a Double In-Law Marriage that would allow him frequent contact with his sisters, is willing to settle for a cousin of his wives to be married to his sisters.
- In the backstory of Dragon Bones, Ward's father was attracted to the Amazonian Beauty Stala, but her ancestry wasn't up to his standards (she was a bastard, apparently), so he settled for her much more delicate (half)sister, whom he didn't respect and mistreated horribly because he viewed her as "weak".
- In Kristin Lavransdatter, Kristin leaves her betrothed Simon for Erlend. Simon ends up marrying Kristin's little sister, but never really gets over Kristin.
- In Jane Austen's Persuasion, Charles Musgrove was once in love with the heroine Anne Elliot. She turned him down, and he married her younger sister. No bitterness seems to exist on either side.
- Sense and Sensibility: When Edward Ferrars refuses to go through with his Arranged Marriage to Miss Morton, his mother disowns him and considers having her younger son Robert marry her (with no one but Elinor wondering how Miss Morton herself feels about this). Ironically, Edward's Clingy Jealous Girl Lucy, whose secret relationship prompted the feud with his mother in the first place, quickly leaves him in favor of his now much-richer brother, which is just fine as it leaves him free to marry Elinor.
- The eponymous character from Clarissa suggests this to Roger Solmes, who wants to marry her, as her sister considers him a good man and Clarissa hates him with a passion. Her family treat this as a huge insult.
- This is narrowly averted in Pride and Prejudice: Mr. Collins comes to town intending to propose to the eldest Bennet sister, Jane. Upon learning she is almost already engaged, he's content to settle for Elizabeth. When she rejects him, their mother hopes he will continue moving down the line and settle for Mary, but he ends up marrying Elizabeth's best friend Charlotte instead.
- Laurie, The One Guy of Little Women, fell in love with Amy aka the little sister of his frustrated First Love Jo.
- In Tess of the d'Urbervilles, Tess knows she is going to die, so she makes Angel promise that he will marry her sister Eliza.
- In the Outlander series of novels, A young priest dying of consumption marries his pregnant lover to his impotent brother while on his deathbed. The baby is the heroine's great-something-grandfather.
- In Like Water for Chocolate, the hero wants to marry the heroine but is told that since she is the youngest daughter, she may never marry. So he marries her sister to be close to her.
- In Harry Potter, Word of God says that George married Angelina Johnson, who had once gone on a date with his twin brother, Fred. Fred is dead by this point.
- Inversion: Ron had a crush on Fleur (well, everyone has a crush on Fleur, but him more than usual), but she winds up with his oldest brother, Bill.
- A variation happens in the short gothic story "The Romance of Certain Old Clothes" by Henry James. Two sisters fall in love with the same man. The man marries one of the sisters, who dies shortly after. He then marries the other sister. The story ends with the jealous ghost of the first wife exacting revenge on her sister.
- In The Color Purple, Mr. initially had asked for permission to marry Celie's younger sister, but was denied by their father, so he marries Celie against her will instead.
- Fathers and Sons by Ivan Turgenev: Arkady is at first interested in Madame Odintsov, but eventually goes for her younger sister Katya.
- This happens in Confessions Of Zeno.
- In North And South, Billy Hazard eventually grows disenchanted with Ashton Main's manipulative behavior and starts to see the beauty and goodness in her sister Brett. When he and Brett decide to get married, Ashton doesn't take it well and arranges to have him murdered on the way to their honeymoon.
- In A Song of Ice and Fire, this appears to be accepted standard procedure in Westeros as most noble marriages are arranged for political purposes: any time a man dies before he can marry his betrothed, she is very likely to be betrothed to any surviving (unattached) brother he has.
- Margaery marries Tommen after Joffrey is killed at their wedding.
- Catelyn Tully is originally engaged to Brandon Stark. But after Brandon is killed by Aerys Targaryen, his responsibility to marry the Tully girl passes to his younger brother Eddard. This turns out to be a Perfectly Arranged Marriage, as they grow to be perfectly happy with each other and have a household of several children.
- Littlefinger seems to be happy with Lysa Tully, as he can't have her sister Catelyn until he pushes Lysa out of the Eyrie. Keep in mind that the Eyrie sits atop one of the highest mountains of the Vale of Arryn. Later on he decides to go after the far more disturbing "Settle for Daughter" with Catelyn's daughter Sansa. Made even squick-ier by the fact that Sansa is posing as his daughter, under the false name Alayne Stone, by that point.
- In Warrior Cats, Berrynose was in love with Honeyfern, but Honeyfern died of an accident. Moons later Berrynose mated with Honeyfern's littermate, Poppyfrost.
- An unusual variant from the Heralds of Valdemar series. Shortly after her father's death young Queen Selenay of Valdemar is charmed by Prince Thanel of Rethwellan and finds herself in a miserable marriage that ends when she is widowed in a "hunting accident"note . Some 15 years later Selenay met her late husband's younger brother Daren in person for the first time and they fell for each other on the spot.
- In Rumer Godden's In This House of Brede, Larry wants to marry Elspeth Scallon, but she becomes a nun. He marries her cousin, Jean.
- In Dune: The Butlerian Jihad, when Xavier thinks Serena is dead he marries her sister Octa.
- Happens a few times in the works of V. C. Andrews. Examples include:
- In the Landry Series, when Ruby marries Paul Tate, Beau marries her twin sister Giselle since he can't have Ruby.
- In the Cutler Series, Jed Booth wanted to marry Violet (Lillian's real mother), but instead married her sister because polite society dictated he should court the oldest daughter.
- A variant in the Logan Series. Cary is heavily implied to be in love with his twin sister Laura, so after she dies, he ends up with their cousin (second cousin, although they don't initially know that) Melody, whom everyone thinks looks like Laura.
- Seeds of Yesterday. Bart thinks he's successfully seduced brother Jory's wife Melodie away from him following the latter being left paralyzed after an accident, but eventually comes to realize he's only a substitute.
- In Poul Anderson's The Un-Man, Jeanne Donner is married to a man who, she does not know, is one of a great Brotherhood of clones. When he is killed in underground work, she is induced to leave her home with their son by another clone, passing himself off as her husband, before his killers capture them both. Later, having learned the truth, she tracks down the clone who rescued her, who had fallen in love with her. When he says he would get over it, she tells him she doesn't want him to.
- In the Agatha Christie novel Sparkling Cyanide, Anthony Brown enjoys an initial flirtation with the married Rosemary Barton, and eventually ends up courting her younger sister Iris. However, it wasn't so much "settling" for the sibling as it was Anthony recognizing Iris's charm and depth of character; he later refers to his feelings for Rosemary as like Romeo remembering Rosaline after he'd first seen Juliet.
- Gone with the Wind. Frank Kennedy thinks he's doing this is regard to marrying Scarlett instead of her sister Suellen, who he's been courting for years, thanks to Scarlett's lie that Suellen's going to marry someone else.
- A variant in Jacqueline Wilson's Hetty Feather series: Hetty's foster brother Jem promises to marry her when they grow up, but after Hetty returns to the Foundling Hospital, she is devastated to learn that Jem has now made the same promise to their younger foster sister Eliza. Ultimately subverted since Jem ultimately marries a third woman nothing to do with the family.
- In Jane Austen's Love and Freindship, Lady Dorothea, who had been Sir Edward's choice for his son's bride, married Sir Edward himself in the end.
- In The Battle of Life by Charles Dickens, Alfred wants to marry Marion with her sister Grace's approval. Marion thinks the two of them should be together instead and stages her own running away to hope this trope will kick in for Alfred and Grace. Which it does.
- Game of Thrones:
- Enforced with Catelyn Tully through Arranged Marriage. After Brandon Stark's death, she married his younger brother Eddard.
- Petyr Baelish, who was in love with Catelyn, had to settle for her sister Lysa. He's not too happy with that.
- A darker version occurs in New Tricks. It turns out that the victim's brother-in-law was the one who put her in a coma. As he "had a thing for Asian note women" and decided if he couldn't have her, nobody could. He tried to make it look like a hate crime and then invoked this trope.
- Mad Men: Anna Draper, upon learning from our Don that her husband (the real Don Draper) never mentioned her, she muses that he actually preferred her sister who "looked like her but had two good legs." Perhaps this is the reason she was so warm and welcoming to the man who stole her late husband's identity.
- One episode of Two and a Half Men revealed that Alan had originally asked out his ex-wife Judith's sister then only dated Judith after she said no.
- Initially played straight and then finally averted on General Hospital. Dr Monica Quartermaine was introduced on the show as the wife of Dr Jeff Webber. It was quickly revealed that she had once been engaged to Jeff's brother, Rick and only married Jeff on the rebound after Rick dumped her and then was promptly presumed dead in Africa. When Rick came Back from the Dead, Monica resumed her pursuit of Rick, but after he became involved with Dr Lesley Williams, Monica decided not to settle for staying married to Jeff and divorced him.
- Keesha got together with AJ following her boyfriend/his brother Jason's brain damage from a car accident (which unbeknownst to Keesha, was caused by AJ) left him not only with no memory of her, but treating her like dirt.
- Battlestar Galactica
- Helo was originally in love with Boomer, who was in love with Chief Tyrol. Helo fell in love with Athena, a copy of the same Cylon model as Boomer, when they were set up together by the Cylons on the planet Caprica, thinking that she was Boomer. Helo married Athena some time after learning the truth, and they became arguably the series' most stable couple.
- Starbuck, who was engaged to Zak, who died before the series begins, but for much of the series she's romantically linked with his brother Apollo. Although they nearly cheated on Zak soon after meeting, so Apollo may not be the one she's settling for.
- On Dr. Quinn, Medicine Woman, the backstory of Loren and Dorothy is revealed to be this—he had courted her back in their younger days before she abruptly married someone else. Her sister consoled him and they ended up marrying.
- On My Name Is Earl, Earl helps a Frenchman he once teased by finding a few girls from their class for him to hook up with. One of the girls was nowhere to be found, but "she had a real friendly sister," who ends up having sex with Pierre in the back of Earl's El Camino.
- House of Anubis- In season two, Eddie brings this up when he thinks Patricia and Alfie might be into each-other, stating that it might be what Alfie is thinking.
Eddie: "Well, He was into Piper, maybe you're just the next best twin."
- In Deadwood, Seth Bullock marries his brother Robert's widow Martha after Robert's untimely death. This is seemingly less about romance and more about acting as a provider for the family and especially a father for Robert and Martha's son William.
- In Hollyoaks, after Becca Dean was murdered, her husband Jake moved on to and married her sister Nancy in fairly short order.
- On The Bold and the Beautiful, Caroline, Taylor, and Brooke all ended up with Thorne Forrester at various intervals, generally because they were fed up with big brother's Ridge's constant waffling between them and Brooke (in Caroline and Taylor's cases), or them and Caroline or Taylor (in Brooke's case).
- One Life to Live: After teen sweethearts Jessica and Christian's relationship fizzled, she ended up with his brother Antonio, while he ended up with her sister Natalie.
- One Tree Hill: Karen Roe was Dan Scott's high school sweetheart, then when she got pregnant with their son Lucas he left, remarried, and had another son, Nathan. Karen raised Lucas as a single mother but was always friendly with Dan's much-nicer brother Keith before it blossomed into romance shortly before his death. This resulted in another child, a daughter named Lily Roe.
- Downplayed on Modern Family: Jay eventually reveals that he'd originally been attracted to Gloria's sister Sonia, and his aborted attempt to flirt with her actually led him to striking up a conversation with Gloria (who he hadn't noticed up until that point) and he ended up asking her out instead. However, it's pretty clear that Gloria is far more his type and that he didn't in any way settle for her.
- Syd Barrett's song "Here I Go" is about a guy who has a crush on a woman who's completely wrong for him, then he meets her sister, finds she's much cooler, and falls in love with her.
- "My Darling Clementine"
How I missed her, how I missed her
How I missed my Clementine
But I kissed her little sister
And forgot my Clementine
- In his rendition on An Evening Wasted with Tom Lehrer, Tom Lehrer turns this into a Gilbert and Sullivan-esque Patter Song.
The Mister resisted
The sister persisted
I kissed her, all loyalty slipped
When she said I could have her
Her sister's cadaver
Must surely have turned in its crypt
- "Happy In You" by Whale
- "Tube Snake Boogie" by ZZ Top.
I got a gal, she lives on the hillShe won't do it, but her sister will
- Maybe not settling, exactly, but The Lovin' Spoonful's "Did You Ever Have To Make Up Your Mind".
Sometimes you really dig a girl, the moment you kissed her, and then you get distracted by her older sisterWhen in walks her father and takes you in line, and says "You better go home, son, and make up your mind."
- "Little Sister" by Elvis Presley is sung from the POV of a guy who was jilted by his girlfriend mid-date (and, apparently, it turns out that she Really Gets Around) and decides to try again with said girlfriend's sister, having noticed that She Is All Grown Up.
Little sister, don't you...
Little sister, don't you...
Little sister, don't you kiss me once or twice
And say it's very nice and then you run
Little sister, don't you do what your big sister does
- According to Jewish tradition, Laban wanted to create a Double In-Law Marriage between his two daughters and his sister's two sons—Leah would marry Esau and Rachel would marry Jacob. Because Esau was a jerk, to say it politely, Leah prayed to God for help, and He arranged events so that both sisters would marry Jacob instead.
- For that matter, the levirate marriage is a similar custom, where a widow marries her deceased husband's brother (or other male relative) if he died childless. However, such a marriage is actually forbidden if the deceased did have children.
- Subverted in the Book of Judges: Samson picks a Philistine woman to marry, but after an argument during the wedding feast, her father concludes that Samson doesn't want her anymore and marries her off to one of his companions. When Samson says that he does still want her, the father suggests he marry her younger sister instead. Samson responded by burning down the Philistines' fields. He had a bit of a temper.
- Classical Mythology has "Settle for Cousin"—Odysseus is one of many suitors for Helen, but her father chooses Menelaus instead. Odysseus hooks up with Helen's cousin Penelope, who turns out to be a much better choice than Helen.
- Inverted: when Paris brought home Helen, forty-eight of his brothers fell in love/lust with her and wouldn't let Priam send her away; the only exception was Hector, who was totally dedicated to his wife Andromache. When Paris died she was married to his brother Deiphobus, in some versions by force; either way, the short marriage was unhappy, and she either celebrated or even helped bring about his death when the city fell.
- According to A Man for All Seasons, Thomas More preferred out of the two, the sister of the woman he married, but chose her because "it was the right thing to do." He, uh, didn't elaborate.
- In Real Life, his motive was that an older sister would, at the time, have found it very humiliating to have a younger sister married first. And they were very happy.
- In the Paul Claudel play The Tidings Brought To Mary, Violaine kisses a leper and gives him her engagement ring to sell for money. Her fiance, upset that she's given away his ring and contracted leprosy, marries her sister instead.
- Twelfth Night has an accidental version. Viola disguises herself as a man and winds up the object of Olivia's affections. Then Olivia meets Viola's Half Identical Twin (whom Viola believes is dead), mistakes him for male!Viola and winds up marrying him before the truth all comes out.
- In the DS version of Dragon Quest V, Debora assumes Crispin has a thing for her, and is just 'settling' for her younger sister Nera. It's obvious to everyone else, however, that he genuinely loves Nera and isn't exactly interested in Debora. Played for Laughs, natch.
- Fire Emblem: Genealogy of the Holy War alludes to this twice:
- Briggid fears that either Jamke or Midayle will pull this on her since they both had Bodyguard Crushes on her younger twin sister Edain. Her love talks with both dudes have them saying this isn't the case.
- Lewyn/Erinys plays with the trope; Lewyn had a major crush on Erinys' sister Annand when he was young, but in a talk event he tells her he's over it and truly wants to be with Erinys now.
- This is optional in Fire Emblem Fates. In Saizo and Kagero's supports, it is mentioned that the two were once a couple, but due to their differences in how they handled being Prince Ryoma's retainers, they ultimately decided to end their relationship so that it would not get in the way of their service. Kagero can then marry Saizo's younger twin brother Kaze, whose calm personality is much more similar to hers. Due to the open-ended nature of supports in the game, however, she can just as well rekindle her relationship with Saizo.
- In Shogo: Mobile Armor Division, Sanjuro, having thought that his girlfriend Kura died two years before the start of the story, has been going out with her sister Kathryn for six months prior to the start. Kathryn loves her sister and is glad to hear that she's alive, but there is some jealousy between them regarding Sanjuro.
- A not-entirely-romantic variation is possible towards the end of Dragon Age: Origins: it is possible to persuade Queen Anora to marry Alistair—the long-lost, illegitimate younger brother of her late husband, King Cailan. Though this marriage is driven by pure pragmatism (Ferelden needs both Anora's firm grip on politics and the Theirin royal bloodline), Anora is shown to have had very tender feelings for Cailan and is slightly confused by the prospect of developing them for his brother.
- Final Fantasy X: This is suggested by Tidus after it comes out that Wakka's dead younger brother Chappu was Lulu's fiance. Lulu dismisses the idea, yet by the sequel (just two years later) they're married with a child on the way.
- In General Protection Fault, Maddie is in love with Fooker, but he refuses to choose her over his girlfriend, Sharon, despite having been separated from her by his UGA deployment, and Maddie insisting that he give up on her. Maddie gets together with Fooker's brother, though.
- Additional weirdness points for the brothers being near-identical in the looks department (besides grooming), and actually sharing a codename; some people aren't aware of the switch.
- In Suburban Jungle, Dover Cheetah eventually switches his affections from main character and unrequited crush Tiffany Tiger to her (half) sister Comfort. As Comfort likes him and Tiffany thinks of him as a friend, this works out well and they beat Tiffany and her beau to the altar by several years.
- In El Goonish Shive Elliot's relationship with Nanase breaks up fairly early on, both because Elliot has feelings for someone else and because Nanase has realized that she's a lesbian. Shortly thereafter, Nanase hooks up with Elliot's sister/daughter/Opposite-Sex Clone, Ellen.
- On Codename: Kids Next Door, Numbuh Two/Hoagie has a Precocious Crush on Numbuh Five/Abigail's older sister, Cree. In the Distant Finale, Hoagie and Abigail are married.
- Hey Arnold! combines this trope with Runaway Groom in the episode "Ghost Bride." It does not end well for the groom and the sister. Or the original bride, for that matter.
- Subverted on The Legend of Korra: Korra has a thing for Mako, who likes her too but is dating Asami. After she has a fight with Mako, his brother Bolin (unaware of all the other drama) asks her out, and she reluctantly agrees, apparently hoping it will help her move on. The two have a great time, but the next day Korra has another fight with Mako, impulsively kisses him, only for Bolin to walk in and have his heart broken. He has majorly gotten over it by the time the first season's over, however.
- In The Simpsons, Marge's high school prom date, Artie Ziff, had a decades-long infatuation with her, but later winds up having a fling with Selma. Their shared dislike of Homer helped to forge an attraction.
- In the third season of Young Justice, Will Harper(Red Arrow), years after his wife Jade abandonned him and their daughter Lian, develops mutual attraction for her sister Artemis. In fact, Artemis' mom actively encourages Artemis to settle with him even tought the latter is quiet reluctant about dating her brother-in-law. Eventually subverted. After a failed first date, Will and Artemis agree to remain friends.
- When Eric Clapton fell for Pattie Boyd and couldn't have her because she was married to his fellow musician George Harrison, he briefly shacked up with Pattie's sister, Paula. Paula ditched him, however, upon realizing that she was just a Pattie substitute.
- Antonín Dvořák initially fell in love with Josefína Čermáková, though she did not love him back and ultimately married another man. Dvořák ended up marrying Josefína's younger sister, Anna.
- Mozart did this. When Aloysia Weber turned him down, he married her sister Constanze. They remained married until his death and seem to have done well together.
- Henry VIII's first wife, Catherine of Aragon, was originally married to his older brother, Arthur. Naturally it was an Arranged Marriage, so when Arthur died young it was agreed that Henry would marry his brother's widow (because you don't give up a strategic marriage to a literal Spanish Princess whose nephew is due to become ruler of one of the greatest empires the world had yet seen,note especially not when she and the new king actually know and rather like each other and seem quite compatible personally). This was somewhat problematic—the concept of affinity meant that the couple was technically considered incestuous, so the pope had to give special dispensation to allow it. When five of the couple's six children later died young (leaving only a daughter) Henry claimed that God disapproved of the marriage and that it should thus be annulled, "justifying" the separation of the English Church from the Roman when the Pope refused to retract the dispensation. This led, eventually, to the end of the Tudor succession/the passage of the English crown to the Stuarts, the English Civil War, and the birth of modern liberal representative democracy. Small trope, big impact.
- Queen Mary, the paternal grandmother of Britain's Queen Elizabeth II, was born Princess Mary of Teck and was engaged to her second cousin once removed, Prince Albert Victor, the son of the Prince of Wales. Six weeks after the betrothal was announced, he died unexpectedly of pneumonia. She and his brother George, now the next in line for the throne (later King George V), began writing letter to console one another, and the following year she became engaged to him instead. It turned out to be an actual love match.
- The fact that they were better match personality wise helped a lot, Queen Mary was having doubts before his death and asked her mother if she could make the marriage a success.
- Speaking of the British Royals, Prince Charles presumably would never have met Diana Spencer had it not been for his romantic relationship with her older sister Sarah, which ended when she seemed to enjoy the publicity too much for his taste (in stark contrast to the shy Diana).
- Princess Dagmar of Denmark was betrothed to Tsarevich Nicholas Alexandrovich of Russia, when he died of meningitis, expressing as a Last Request that she marry his younger brother Alexander, which in due course she did.
- According to his biographer and son-in-law William Roper, St. Thomas More actually preferred the younger sister of his first wife but proposed to the elder because it would have humiliated her to see her little sister married first. Other biographers have suggested that Roper mistook a family joke for fact. Will had no sense of humor and More had a very good one.
- Joseph Haydn was in love with Therese Keller, but she decided to enter a convent. So he married her younger sister Maria Anna instead. Unfortunately, the marriage turned out unhappy for both of them.