This is a subtrope of Love Triangle where the central character has two options of different sexes or genders. The conflict comes from having to choose between a same-sex and an opposite-sex relationship, as society still treats both very differently regardless of how the character themselves feels about it. Choosing the gay option might mean facing discrimination, while choosing the straight option might be seen as "settling" or "not actually bisexual". Historically, instances of this have ended very poorly for the same gender member—with gayngst being common, the same-gender love interest often giving up on their affections, and them almost always never being treated too seriously due to Incompatible Orientation. Newer works are more likely to make the triangle an actual choice by having the central character be outright bisexual or have feelings for both anyway.
This is common in coming-out-stories where the character is still figuring out their sexuality. It also often overlaps with Closet Key. As a result, there's no rule for the character to be any particular sexuality and it does not just apply to characters who are bisexual (although this is the most common version). It may be a gay or straight character who is "confused" about their sexuality or trying to figure themselves out. In this case, it will usually involve a Last Het Romance.
Stories which prominently feature a Gender Bender will often give the affected a pair of opposite sex love interests. These tend to implicitly or explicitly involve Trans Equals Gay, connecting a relationship with their former sex to identifying with their current one. Some combination If It's You, It's Okay and Jumping the Gender Barrier is typically involved. However, if a character is a casual Sex Shifter, such a mix of different loves could be considered with much less conflict.
Compare and contrast Everyone Is Bi, which is when bisexuality and the sexes and genders of potential love interests are portrayed as no big deal. Even then, though, due to the different expectations around homosexual vs. heterosexual couples, this trope may still apply.
But Not Too Bi might come into play when it comes to choosing a winner — the character may express interest in both of their love interests, but will get with the one whose sex/gender they have been dating more often, or the one the target audience considers more "acceptable" (for a long time in mainstream media this would be the straight option, but Queer Media might lean towards the same-sex option).
Please note that this trope does not include all Love Triangles where the central character happens to be bisexual. Relationships between the male and female love interests must have different connotations that affects the main character's decision (or lack thereof). Compare Betty and Veronica for another way to play a "safe vs. more dangerous" love triangle. Due to the gender dynamics inherent in the bisexual love triangle, this may also cross over with Brooding Boy, Gentle Girl, Male Might, Female Finesse, Masculine Girl, Feminine Boy, Savvy Guy, Energetic Girl, or Strong Girl, Smart Guy.
If this love triangle gets too dangerous, it may play into Depraved Homosexual, Psycho Lesbian, or Depraved Bisexual stereotypes, and may, under certain circumstances, fall completely into Psychotic Love Triangle.
- In After School Nightmare, protagonist Mashiro was born intersex but identifies as male and is torn between the girly and androphobic Kureha and the cold and dominant Sou. This love triangle represents Mashiro's conflicting feelings about his gender - he is happy to date Kureha as it puts him in a masculine position, but is uncomfortable with his attraction to Sou because he worries that it's proof that he's 'really' a girl. (Somehow, the idea that he might just not be straight doesn't come up.)
- The core of Blue Flag's drama centers around Taichi, who's torn between his feelings for the female Kuze and his old male friend Touma. While Taichi does eventually begin dating Kuze, Touma's love for him and the fallout of what happens when the rest of the school finds out he's gay causes him to reevaluate both relationships to worrying results.
- At the start of Boku Girl, Mizuki is in love with Yumeko, who loves his friend Takeru. Then Mizuki's sex transformation causes him and Takeru to develop feelings for each other. Which one Mizuki would rather end up with is intertwined with his conflict on whether he wants to be male again or embrace being a girl. In fact, Loki ultimately makes it so Mizuki will be the opposite sex of whichever he falls in love with, and the resolution follows the First Law of Gender-Bending and No Bisexuals: Despite Mizuki's expectations, Yumeko falls for him, whether he decides to identify as a boy or girl. However, Mizuki realizes he never really loved Yumeko, while being turned male again didn't diminish his love for Takeru. So Mizuki chooses to start dating him, as a girl.
- Destiny of the Shrine Maiden: Himeko habors feelings for both her childhood friend Souma (male) and Chikane (female). In the end she chooses Chikane. Chikane and Himeko are destined to be together anyway.
- Please Save My Earth: Combined with Reincarnation Romance- in their original incarnation, Issei and Alice were both female, and were both potential love interests for Jinpachi. Things become more complicated when Issei is reincarnated in a male body. Jinpachi is straight, but has lingering feelings for Issei anyway.
- The Rose of Versailles has a triangle with both Rosalie (female) and André (male) as the admirers to Lady Oscar (female). Both are forbidden romances — Rosalie because she's a woman, and André because he's a servant.
- Harley Quinn and Poison Ivy's relationship has primarily been this way since they met in Batman: The Animated Series (though DC kept it as subtexty as possible for years). Harley is head-over-heels for her boyfriend, The Joker. The Joker is extremely physically and emotionally abusive but Harley always goes back to him in the end. Ivy on the other hand has feelings for Harley and the two have a much more stable relationship, but Depending on the Writer Harley is either oblivious, knows of Ivy's feeling but ignores her, or has flings with Ivy when she and the Joker are separate. Starting with the New 52 reboot, DC revamped Ivy and Harley's relationship to be more obviously romantic and requited. They're either Friends with Benefits or a non-monogamous couple.
- Naked Singularity: The titular romance novel has its heroine Evening Glimmer urged to choose between Prism Slash (male) and Uncommon (female). At one point Uncommon suggests that Evening Glimmer should choose her because of the joy only another mare can give her.
- In Basic Instinct, Catherine is in a Psychotic Love Triangle with her female lover—and murderer—Roxy, but she is also deeply attracted to the more conventional, strait laced protagonist Nick Curran, although her decision is between killing him (which Roxy seems to want) or corrupting him to kill someone for her, or both, and Nick himself is actually the protagonist, which means that he's mostly fighting Catherine's impulse to kill him courtesy of Roxy. The ending ultimately has her "choose" him after Roxy's death - and Catherine is not interested in monogamy anyway - but it remains ambiguous how long it's going to last. Will she kill him straight after they have sex? Has he briefly convinced her not to?
- Chloe: It starts off with Catherine hiring sex worker Chloe to seduce her flirtatious husband to see if he's being unfaithful, but Catherine later winds up torn between David (her longtime husband, whom she loves despite their marriage being en route to Dead Sparks) and the younger and more exciting Chloe. Turns twisted when it turns out that Chloe is Catherine's mentally unbalanced stalker. Following Chloe's death at the end, David and Catherine are implied to rekindle their marriage.
- Happiest Season: Harper is a lesbian who is not out to her old-fashioned family, but has brought her girlfriend Abby home for the holidays (under the pretense of being her orphaned roommate). Harper's parents try to get her back with her high school boyfriend Connor, who represents Harper's closeted life in a small conservative town. This is juxtaposed against her relationship with Abby, whom she is hiding; Abby in turn represents Harper coming out and being true to herself around her family.
- Jennifer's Body: Jennifer and Needy have always had an intense Romantic Two-Girl Friendship, which included bed sharing (and they make out at one point). Needy is also in a relationship with Chip and only shows attraction to other guys, such as Colin. While all the boys want Jennifer, her only really sincere romantic relationship is with Needy but the arc of the movie is ultimately about Needy realizing what a Poisonous Friend Jennifer is. Jennifer kills Chip (and Colin) because she wanted to take what Needy had, so ultimately, Needy killed Jennifer in revenge and to stop her from hurting anyone else. Nevertheless, she inherited some of Jennifer's powers and used them to avenge her at the end.
Needy: I thought you only killed boys!
Jennifer: I go both ways.
- One interpretation of Mulholland Dr. is that the lesbian Diane is in Mad Love with the beautiful presumably bisexual Camilla, who broke up with her for Adam, the wealthy, successful, and sleazy film director. This led to a Psychotic Love Triangle and If I Can't Have You..., culminating in Diane hiring a hitman to kill Camilla. Unusually for the trope, it would then take place in the past, from the position of the losing party. However, in another twist to the usual trope, despite being in a relationship with a man, Camilla seems to have already replaced Diane with another woman. Maybe
- Alluded to in the film version of RENT when Maureen storms out of her and Joanne's engagement party after an argument about a woman checking her out. Maureen's parents turn to Mark, asking him if he'll now get back together with her. While Mark is respectful of his ex's relationship, her parents are enforcing the love triangle to give Maureen a straight option (this is 1990, after all).
- In Yves Saint Laurent, Yves's lover Pierre seduces Yves's best friend Victoire because he's jealous of their closeness.
- There is an old Russian joke where three people are stranded on an uninhabited island; a prostitute, a gay and a cadet. The cadet has a loaded gun. After some time, the prostitute whispers to the cadet "Hey, how about you shoot that gay, and we'll start living a normal sexual life?" Some time later, the gay whispers to the cadet "Hey, how about you shoot that tramp, and we'll start living a normal sexual life?". The cadet thought, shot them both, and started living a normal sexual life.
- In Gena Finn, "straight" girl Finn, who is in her early twenties, realizes she may actually be bisexual after developing a deep Romantic Two-Girl Friendship with the lesbian teenager Gena over the Internet. However, Finn is already engaged to Charlie, a Nice Guy who financially supports her and helps her out of her post-college rut, but only wants to settle down. Gena, meanwhile, is a younger deconstruction of the Manic Pixie Dream Girl, as a former child star with severe mental health issues, but who understands Finn's creative spirit and bonds with her over their favorite television show, for which they write fanfic together. Finn ditches Charlie for Gena after Gena has a psychotic break, openly admitting that she doesn't know if she has feelings for Gena, only that Gena "needs" her right now. Finn ultimately realizes that Gena needs a friend and emotional support, and so she gets back together with Charlie but Charlie makes room for Gena in their lives, and Finn and Charlie more or less act as Gena's parents.
- The Homestuck Epilogues: In the "Candy" route, after a polyamorous relationship with the two falls flat, Dave is trapped between his safe marriage to Jade and his attraction to Karkat, the latter having left their family to become a revolutionary.
- Labyrinth Lost: Heroine Alex spends the entire book having to decide whether to be with her best friend Rishi or bad boy Nova, with it being a choice between a friend she's known for a long time or a passionate relationship. She eventually chooses Rishi, with Nova and her settling for just being friends.
- Seraphina: Seraphina Dombegh ends up in between the affectations of both Prince Lucian Kiggs and his cousin Princess Glisselda who are both head over heels in love with her. Kiggs is an example of Star-Crossed Lovers with Seraphina while the latter is her best friend who awakens feelings within her that she didn't know she had. Eventually it's implied in the companion novel that she ends up with both of them, with all three living a happy polyamorous relationship.
- Atypical: In the first season, Casey seemed to be straight-up heterosexual, having sex with her boyfriend Evan. However, come the second season she started to question her sexuality with a girl, Izzie, whom she meets at her new school Clayton Prep. By the third season, she is torn apart by her attraction to both of them, but ultimately goes with Izzie over Evan — that isn't to say she didn't break down crying when she broke up with Evan.
- Several in Black Mirror.
- In "San Junipero", Kelly is in one with Yorkie and her husband, although her husband is dead. Kelly promised her husband so that she would "move on" and not go to San Junipero, because their daughter died before she had the option. Yorkie, however, who has been lying paralyzed since she was a teenager, represents the possibilities of San Junipero and the new life it provides. Kelly eventually chooses Yorkie.
- In "Striking Vipers", Danny is in one with his wife Theo and their old friend, Karl. While it's played straight for most of the episode — with Theo representing stable family life and Karl representing sexual fulfilment through online methods — played with at the end. It turns out that Danny is only attracted to his male friend when he's playing as a woman. So he and Theo compromise, having sex the rest of the year, except for one day, where he has cyber-sex with his male friend as a woman.
- Buffy the Vampire Slayer: After Oz leaves Willow (and Sunnydale) to find a cure for his lycanthropy, Willow grows closer to her fellow witch Tara and finds they have a deep bond in magic. When Oz returns, seemingly cured, his anger at realizing Tara is falling for her brings his werewolf side back out. Deciding between a gentle, magical relationship with Tara and the possible danger Oz brings, Willow ultimately chooses Tara (and identifies as gay moving forward).
- In Euphoria, trans girl Jules is pursued by Jerk Jock Nate (although she doesn't know it's him at first, thanks to the Internet), and female best friend Rue. Since her transition, Jules feels the need to sleep with random men from the Internet to feel validated, which Nate (in his persona of "shyguy"), gives her. However, Jules didn't know that Nate was catfishing her because she had sex with his dad. Rue, meanwhile, genuinely and near-unquestioningly adores Jules, but also depends on her for her sobriety, which leads to Jules meeting Nate in person and being blackmailed by him. Nate's obsession represents Jules' desire to be comfortable with her gender and her need to keep her secrets, while Rue provides Jules with genuine love, but can also fall into being manipulative by needing Jules too much, so Jules feels suffocated by providing Rue with stability.
- In Glee, there is a brief love triangle between Kurt, Blaine, and Rachel. Blaine, who had previously thought he was gay, drunkenly kisses Rachel and thinks he might be bi. This love triangle is obviously important in Blaine working out his sexuality (still 100% gay). Kurt, who really likes Blaine, gives him a negative speech about how he can't like Rachel because bisexuality isn't real, sparking an argument between them.
- Kalinda in The Good Wife slips into one of these with FBI agent Lana Delany and Carey Agos. As Kalinda Really Got Around, in a demonstration of All Gays Are Promiscuous, the question is more about whether Kalinda can choose between them, or whether she's happy just to use both of them for information. Lana gets derailed at the end of Season 5, as she's seen being accused by her boss of leaking information, and that's the last we see of her. However, Kalinda doesn't end up with Carey either, after this - she has to skip town, so it's an Aborted Arc.
- The Haunting of Bly Manor is about a metaphysical one. Dani is not bisexual - she's a closeted lesbian - but she is still holding onto her ex-fiance and childhood best friend, Eddie's, ghost because she blames herself for his death moments after she broke up with him due to realizing her sexuality. As she falls in love with Jamie at Bly, she has to learn to let go of Eddie for her future happiness.
- Killing Eve presents a psychotic version between Eve, an apparently straight married woman, who becomes obsessed with lesbian serial killer / assassin Villanelle. Eve's husband, Niko, is completely disgusted by the violence that Villanelle brings into their lives, and Eve's growing attraction to it, meaning that Eve has to choose between Villanelle and homicidal chaos or Nico and boring normality.
- Lost Girl: Bo, a succubus fae, not only has strong feelings for Dyson, a male werewolf Fae, but for Lauren, a female human scientist working with the fae. Initially, Bo tries to keep her distance from Lauren, as she hasn't figured out how to fully control her drain-life-via-sex powers, and "feeds" off Dyson fairly regularly because fae have more life to give, so she can feed without killing him. As the series progresses and Bo learns to control her powers more (and various characters' dark secrets start coming out), the situation develops into a full-blown love triangle, with jealousy, betrayals, suspicion, and angst.
- The Murders: This turns out to be the root of the rivalry between rappers Lil Rex and DB Kane. Lil Rex was publicly dating Ayanna, but he also had feelings for DB Kane. However, as both men were still in the closet fearing backlash to their careers, no one but the three of them knew. This worked for a while, until Lil Rex accidentally got Ayanna pregnant, and feeling he had to step up broke it off with Kane. Heartbroken and humiliated, Kane started a feud with Lil Rex. Following Lil Rex having a breakdown, Kane and Ayanna agreed that he needed both of them, and finally came out with the truth, deciding to see how polyamory worked for them.
- In Mrs. America (a show set in the 1970s), real-life activist and lawyer Brenda Feigen, who is Happily Married to her fellow attorney Marc Fasteau. However, she has a liaison with a female photographer named Jules and starts questioning her sexuality. She later finds out she is pregnant by Marc, who thus represents her traditional family life, while Jules represents something unknown and exciting.
- Season 3 of The Sinner. Although Jamie denies that his and Nick's relationship was explicitly sexual, they had a lot of Homoerotic Subtext which is why everyone keeps asking him. Jamie was divided between Nick and his wife Leela. Nick wanted him to kill Leela and others, and let in his inner "ubersmench". Leela is heavily pregnant and just wants to settle down with him. Jamie left Nick to die, but the Psychotic Love Triangle didn't even end there as Jamie is still haunted by him and his mind games after his death.
- The Life Is Strange series give the protagonists a love interest of at least one of each gender, with the exception of the prequel Before The Storm. The different genders are given their own weight and problems.
- In the first game, Chloe is the first girl that Max has ever been attracted to while Warren is Max's friend that she might like to have something with. At the end of the game Max has to decide if she will save Chloe at the cost of the rest of the town, Warren included.
- The second game has at one point, have Sean decide between expressing his attraction to either Cassidy, where he can lose his virginity, or Finn, where he can explore his newfound knowledge of being attracted to other boys. Notably, he shows his attraction to both of them in his journal before the episode even starts. If Sean leaves for Mexico without Daniel, then whoever he romances will join him.
- True Colors has protagonist Alex form a relationship with either her late brother's best friend Ryan, or her co-worker Steph.
- In Act 6 of Homestuck, both Jane (female) and Dirk (male) have romantic interest in Jake. Jane, and Jake himself at first assume that Jake is primarily interested in women, and as such wouldn't be receptive to Dirk's advances, but Jake comes around and acquiesces to Dirk. This establishes Jake as bisexual and really gets the comic's Everyone Is Bi theme going.
- Ménage à 3 is basically a webcomic about a gigantic and tangled bisexual love polyhedron, though actual romantic love seems fairly rare. Notably, at the end, Zii seems torn between DiDi and Gary.
- Pixie Trix Comix is a spin-off of Ménage à 3 (see above) with a similar tendency to bisexual complexities. Notably, the sexually confused Aaron is taken with both Julian and Nikki.
- Questionable Content: Elliot is romantically interested in both Clinton and Brun, which is complicated by the fact that Clinton considers himself straight but potentially receptive to the right guy, and that Elliot Cannot Spit It Out to either of them. Ultimately, the truth comes out, Clinton realizes he's attracted to Elliot, and they end up together — to Brun's approval, as she isn't interested in either of them.
- Sandra on the Rocks, another spin-off of Ménage à 3 (see above), inherits its tendency to bisexual triangles, notably including the relationships between the title character Sandra, her boyfriend Pierre, and whichever woman is attracting Sandra during her latest bender, but especially Cammi. As a comedy bonus, at one point, Alex finds himself torn between Eloise and Eloise disguised as a guy.
- Sticky Dilly Buns is yet another spin-off from Ménage à 3 (see above) that heavily exploits this trope. The main example would be Jerzys interest in both the male Dillon and genderfluid Angel.
- Big Mouth does this with Jay but for his bisexual awakening. Though, in this case its between his female pillow and the male couch cushion. He tries to spend equal time between them and force to choose which one he prefers. He realize he likes both of them but for different reasons.
- Harley Quinn: In the second season, Poison Ivy is torn between a thrilling life of crime and fun with her best friend Harley Quinn and a stable life with the bland but kind Kite Man. As Ivy explains it, she loves Harley but can't trust her, because Harley is flighty and impulsive and Ivy fears being left behind. On the other hand, Kite Man is trustworthy and stable. Harley wins. Kite Man is simply not compatible with what Ivy wants out of life and Harley slowly, but surely becomes more reliable.
- Steven Universe: The flashback episodes focused around Greg as a young twenty-something dating Rose depict a constant conflict between Pearl and Greg over Rose's affection, where the former is a big Clingy Jealous Girl who tries to chase Greg away so she can have Rose to herself. The narration implies a major reason why Rose went for Greg over Pearl is because Greg was the first person to treat Rose like they were on the same level, while Pearl put Rose on a pedestal and idolized her. The usual gender connotations are reversed, as Rose and Pearl are aliens from a Nonheteronormative Society, so Greg's inclusion is treated as more unusual for being an Interspecies Romance.