History Main / SiblingTriangle

* A common variation of this common in Otome Games is to have a ThemedHarem around this for those who want siblings. but no BrotherSisterIncest (although in ''LightNovel/BrothersConflict'''s case it's NotBloodSiblings[[spoiler:...[[ObliviousAdoption twice]]]]). Other examples include:

* ''Film/{{Crush|2022}}'': Sisters AJ and Gabby both like Paige. At first, Paige liked Gabby, then AJ. After it comes out, AJ temporarily shuns Paige because it seems like she'd been used and doesn't want to be second picked either. [[spoiler:Gabby realizes what's happened and urges AJ to get back with Paige. TheyDo at the end.]]

If they don't hate each other from the start the TriangRelations version of the triangle is a special subset of #8 or #9. If the former, it will turn into a case of {{Polyamory}} (if they're twins, it can also be a TwinThreesomeFantasy). If one of the siblings is the non-related party's official partner and there's cheating involved with the other sibling, it overlaps with AFamilyAffair.

* In ''Anime/RevolutionaryGirlUtena'', both [[spoiler: Anthy]] and her brother [[spoiler: Akio manage to bed Utena ''and'' each other ([[RapeAsDrama not very willingly from Anthy's side, though]]).]] A type 8 TriangRelations with some positively disturbing sex scenes. [[spoiler: Nanami]] finds out and is traumatized by the knowledge, so she tries to warn [[spoiler: Utena]] [[TheCassandra to no avail]].

* ''Series/{{Arrow}}'' has the Lance sisters -- Sara and Laurel -- who competed rather bitterly for Oliver Queen's affections. Oliver doesn't help matters by becoming engaged to Laurel, then inviting her sister to come on the Queen's Gambit with him because he has CommitmentIssues. Sara goes along with this because she's infatuated with Oliver and likely also out of petty revenge on her sister. Although Laurel does eventually forgive Oliver, and later Sara when she too comes BackFromTheDead in Season 2, the affair is shown to hang over all three characters throughout their lives.

* ''LightNovel/MyNextLifeAsAVillainessAllRoutesLeadToDoom'':
** Prince Gerald worked hard to keep his brother Alan from realizing that he was in love with Catarina in order to avoid this trope and more rivals, but Alan eventually catches on and begins pursuing Gerald's fiancee Catarina, who isn't really interested in either of them because she's too in love with cake to notice anything else.
** Sophia and Nicol also both have a thing for Catarina, but in this case Sophia seems to want her brother to marry Catarina [[BigBrotherAttraction so that she can have them both]].

* PlayedForLaughs on ''WesternAnimation/PhineasAndFerb,'' when [[FailureIsTheOnlyOption Candace]]'s KidFromTheFuture refers to [[TheChick Isabella]] as her aunt.

* ''VideoGame/LoveAndPies'': Amelia falls in love with her ChildhoodFriend Joe after she divorced her husband. They rekindle their lost relationship over the course of the game, but [[spoiler:Joe's twin brother Sam pretends to be him to try seducing her while the real Joe is at the two-day baker's retreat. Sam still tries pursuing her after he's exposed because he fell in love with her for real, but she's having none of it.]]

** The series also features the very rare example where ''all'' of the parties involved are siblings. Aegon IV's bastard children Brynden Rivers, Aegor Rivers, and Shiera Seastar were involved in a love triangle that, according to Barristan Selmy, tore apart the Seven Kingdoms. Brynden and Aegor both loved Shiera, who was affectionate to Brynden but never fully reciprocated it. Brynden and Aegor happened to take different sides of more than a century-long civil war, which only added fuel to the fire.

** In the distant backstory, in accordance with Valyrian tradition, Aegon Targaryen (later known as [[FounderOfTheKingdom Aegon the Conqueror]]) was [[ArrangedMarriage required]] by his parents to marry his [[BrotherSisterIncest older sister]] Visenya, but he was in love with his younger sister Rhaenys. His solution was to [[MarryThemAll marry both of them]], which was unusual, but allowed. Understandably, Visenya was not happy about having to share a husband with her sister, especially since Aegon favoured Rhaenys and named their son Aenys as his heir instead of Visenya's son Maegor, who was much more martial and warrior-like. She's widely thought to have gotten got her revenge ([[RevengeByProxy sort-of]]) long after her siblings' deaths, when she poisoned her [[EvilStepmother stepson]]/[[EvilAunt nephew]] when he sought refuge with her and [[MotherMakesYouKing installed]] Maegor on the throne after Aenys's death. Eventually, she lost out when Maegor died without issue and the throne passed to Rhaenys' son Jaehaerys, and all Targaryen kings since then were descended from Rhaenys.

If they don't hate each other from the start the TriangRelations version of the triangle is a special subset of #8 or #9. If the former, it will turn into a case of {{Polyamory}}. If one of the siblings is the non-related party's official partner and there's cheating involved with the other sibling, it overlaps with AFamilyAffair.

* A variation occurs in one of the ''Manga/TheLegendOfZelda'' manga based off of ''VideoGame/ZeldaIITheAdventureOfLink''. The current Zelda and the recently-revived Sleeping Zelda both fight over Link at the end. They're distant relatives as the latter had been comatose for centuries, and the current Zelda is presumably a descendant of her brother.

* In ''Manga/BlackClover,'' [[IllGirl Finesse]] is introduced as [[ArrangedMarriage the betrothed]] to whomever becomes the new head of House Vaude--implying that their father was already planning to disown older son [[NoRespectGuy Finral]] for his more talented half-brother [[ChildProdigy Langris]]. Finral and Finesse would be a PerfectlyArrangedMarriage; Langris is initially indifferent to Finesse, but his InferioritySuperiorityComplex is such that he's enraged at the thought of ''anybody'' preferring Finral to him. [[spoiler:[[ShipperOnDeck This seems to have changed]] after some CharacterDevelopment]].

* In ''VideoGame/TheKingOfFighters'' RadioDrama ''The Sun and the Moon'', [[AntiHero Iori Yagami]] finds himself in a triangle with his two {{Morality Pet}}s, the sisters [[BrokenBird Konoe]] and [[IllGirl Kikuri]] Tanima. [[spoiler: He ends up with… neither of them: he leaves Japan [[ItsnotYouItsMe to protect them from himself]], and Kikuri dies of illness later.]]

* In ''Manga/CardcaptorSakura'', elementary schooler Sakura's first crush is her teenage brother Touya's best friend, Yukito. Touya and Yukito are in love with each other, but haven't actually talked about it for most of the series. They are both incredibly kind and patient with Sakura over the whole thing, pretending to be oblivious and going along with it whenever Sakura asks him to bring Yukito over so she can give him some token of affection. Yukito waits until Sakura actually tells him about it to let her down as gently as he can, by comparing her love for him to her love for her father. Sakura immediately guesses that it's Touya he really loves, which Yukito confirms and Sakura is both heartbroken and thrilled by, eagerly reminding Yukito just how sweet Touya can be when he wants, how sure she is that Touya loves him just as much, and to come to her if he ever gives Yukito a hard time.

* In ''Manga/CardcaptorSakura'', elementary schooler Sakura's first crush is her teenage brother Touya's best friend, Yukito. Touya and Yukito are in love with each other, but haven't actually talked about it for most of the series. They are both incredibly kind and patient with Sakura over the whole thing, with Touya pretending to be oblivious and going along with it whenever Sakura asks him to bring Yukito over so she can give him some token of affection. Yukito waits until Sakura actually tells him about it to let her down as gently as he can, by comparing her love for him to her love for her father. Sakura immediately guesses that it's Touya he really loves, which Yukito confirms and Sakura is both heartbroken and thrilled by, eagerly reminding Yukito just how sweet Touya can be when he wants, how sure she is that Touya loves him just as much, and to come to her if he ever gives Yukito a hard time.

* In ''Manga/CardcaptorSakura'', 10-year-old Sakura's first crush is her teenage brother Touya's best friend, Yukito. Touya and Yukito are both in love with each other, but have stopped just short of talking about it for most of the series. They are incredibly gentle with Sakura over the whole thing, with Touya going along whenever Sakura asks him to bring Yukito over so she can give him some token of affection. Yukito waits until Sakura actually confesses to him to let her down, and Sakura immediately guesses that it's Touya he really loves, which Yukito confirms and Sakura is both heartbroken anc thrilled by, eagerly reminding Yukito just how sweet Touya can be when he wants and to come to her if he ever gies Yukito a hard time.

* In ''Film/KrushGroove'', [[Music/PrincesAssociates Sheila E.]] is in a love triangle with brothers Russell and [[Music/RunDMC Run]] and chooses Russell, telling Run she sees him as JustFriends.

* Taken UpToEleven with ''Manga/FruitsBasket'', which is arguably the TropeCodifier for Sibling-{{Themed Harem}}s that don't resort to BrotherSisterIncest. The main one involves Yuki and Kyo, who are actually cousins, but living in the same house as their love interest Tohru, it has this vibe. [[spoiler: Kyo wins, and Yuki's affections get weirdly explained away as non-romantic after all.]]

* A common variation of this common in Otome Games is to have a ThemedHarem [[UpToEleven around this]] for those who want siblings. but no BrotherSisterIncest (although in ''LightNovel/BrothersConflict'''s case it's NotBloodSiblings[[spoiler:...[[ObliviousAdoption twice]]]]). Other examples include:

* In Adachi Mitsuru's ''Manga/{{Touch}}'', twin brothers Katsuya and Tatsuya both love their childhood friend Minami. Older twin Tatsuya backs off, allowing the younger Kazuya to win at everything, including love seemingly. Then… Kazuya dies in an accident, and the story follows the relationship that develops after this tragedy.