Oswald:Forget it. I don't wanna talk about this. Lewis:No, no, I'm curious. Let's say you're in prison, and you're not getting out for a very long time. Plus, your parents? Very understanding. Who's your cellmate? Oswald:...Liam Neeson. Drew: (wrapping an arm around Oswald's shoulders) Aye, laddie!
A character's assumed actual romantic preference or even sexual orientation is made moot because of the setting or limitation of the plot. This frequently occurs with characters stuck in a gender-biased population. (see: Bishoujo Series and Cast Full of Pretty Boys). Even if there's a theoretical pool of candidates off-screen, savvy writers know the audience likely doesn't care. This arises when writers apply standard romantic tropes to quirkier settings without major modification and without the explicit intent to make a plot point about it. If the situation developed after the plot is well underway, this may also be Suddenly Sexuality, or at least played as such.
Some writers are fully aware of the implication and the fandom it produces and might cater to both sides of the topic, making one character very enthusiastic about the idea, while one is humorously much more hesitant.
A common by-product of this trope is the rejection of a newly introduced 'common' romantic prospect, not because of a strong pre-existing fanship, but simply that they never reach the popularity of the existing cohort.
Not to be confused with If It's You, It's Okay.
And the two lead characters avert the trope entirely: they are quite thoroughly lesbian, as illustrated by the manga's epilogue that takes place after high school.
Mai-Otome establishes via Technobabble that the girls' Otome powers go away if they have sexual relations with men. This is odd in that male characters are still around, and with one exception, none of them are involved romantically with other Otome, presumably so that the writers didn't upset the sizable yuri fanbase.
Note that its heavily implied in-universe that the inventors of the system that gives them their powers did this on purpose, although whether its because they're idiots, Yuri Fanboys, or there was some other consideration involved, is never made clear.
Vandread reverses it. The two cultures start off unfamiliar with the idea of gender at all, but when encountering each other for the first time, some of the women and all three of the captured men turn out to be straight (or at least bi). Not that they have any idea why they find the "aliens" more attractive than their own kind...
Then again, when one of the only three males (at least that we knew of immediately) had a Bridget dropped on him, he decided he didn't care anymore and continued his pursuit anyway.
One of the women finds a book that explains heterosexual sex and reproduction. She wants to try it but the way she goes about it with the youngest male available and the fact that she has a girlfriend suggest that she doesn't really comprehend the importance. She also gets accused of witchcraft when the female government finds it in her possession. It sounds funny. It was not.
Saber Marionette J, where the world is all male because the only survivors of the spaceship crash were male, and since not-so-logically everyone is a clone from the DNA of those six, there aren't any women. If they can do cloning, why can't they do X-chromosome duplication? Never mind. Oddly enough Robot Girls in the series are mostly treated as impressive machines, but Hanagata is the only real obviously gay character. It isshonen, after all. The manga states outright that lack of women is the reason for most of the homosexual relationships on Terra 2.
One storyline in the manga Gohou Drug involves the characters infiltrating an all male boarding school, where almost all the guys are gay simply because there are no girls around. One student even explains this trope directly to the main character.
The Arume in Blue Drop form a race that only consist of women, but they manage to produce offspring with the aid of technology. After conquering the earth they still appear to be mostly interested in the women though.
Also happens with Earth's people in the manga, Tenshi no Bokura. The Arume keep the humans segregated by gender, so the girls grow up lesbian due to Arume... influence. Males resort to homosexuality out of necessity, although one of a pair often crossdresses.
There is absolutely no appearance or mention of any female in Boys Love anime Sukisho, and the Valentine's Day episode shows many gay couples walking around. There is no explanation for this, females simply seem to not exist. The lead character's reaction to gayness still goes from absolutely-unbothered to completely-freaked-out (and oblivious-to-his-roommate-in-denial).
Jyu Oh Sei: Women are very scarce on Chimera, and tend to live separately from men. As a result, a lot of otherwise straight men aren't against going for the next best thing (read: Thor)
An example of either this or Bi the Way appears in Black Lagoon, Revy states that she had sex with women in prison, however, her love interest is a guy. Fans debate whether her interest women extends outside of prison, since in context she was referencing being with women as a threat to make another woman her bitch.
In Y: The Last Man, a lot of women are with other women as a substitute, but a lot simply go without, as many of them had before the "Gendercide".
Writers of Wonder Woman throw around hints that Themyscira has embraced this sort of mindset: some of the women are chaste, some of them are seeing Rosie Palms, and the rest pair up.
The more juvenile writers, usually the ones who get a chance to briefly play with the character in another title, throw around hints. The main series itself has straightforwardly confirmed it multiple times, though quietly.
Diana does some traditional courtship rituals with her boyfriend Nemesis, he asks how a society of only women has such things.
A throwaway line a while ago basically said Queen Hippolyta is in a relationship with General Phillipus, and Word Of God confirmed it (as well as the fact that they intended to do a storyline where they got married before the editorial axed it).
The Buffy The Vampire Slayer Season Eight comics have Buffy hook up with fellow Slayer Satsu. It is shown as a result of Buffy feeling emotionally isolated (not to mention sexually-deprived), so she latches on to Satsu (who is genuinely in love with Buffy). This is similar to her relationship with Spike, where she also chose a unusual partner (a soulless corpse in that case) who was genuinely in love with her, in order to satisfy her (purely physical) needs (though at least Satsu she liked and respected, while she frequently professed outright disgust and rage at Spike during season six).
Hilariously, it was Satsu who broke off the relationship with Buffy... and then spent an entire issue wangsting about Buffy rejecting her, despite this never having actually happened.
With a setting that includes only two canonical male characters (and only one of them is even given a name!), this trope grows like kudzu in the Touhou fandom.
That being said, ''Perfect Memento in Strict Sense'' illustrates (literally) that there are males in the human village. Whether or not any of the youkai girls would be interested (although the presence of Rinnosuke would indicate it's possible), the human characters should have their pick of straight options. However...
Lord of the Flies fanfiction is often subject to this, since there are no female characters...period.
The Team Fortress 2 characters are seen (and promptly used) as such. As best said by Kytri, author of Cuanta Vida, "I think of most of the characters as being straight, you just wouldn't notice since there's no women around for them to be straight with."
Jack: There's only two times when that kind of thing's okay: In prison where it's a substitute and guys in space.
Mike: Guys in space?
Jack: Well, not on purpose. They just float into each other.
Possible heterosexual variant in a early script for Alien, were Ripley tells Dallas she "needs release" and starts taking off her clothes, probably because they are confined to a spaceship with a small crew for large amounts of time, or this could be implying a relationship between the two. (It's worth mentioning that, in earlier drafts, the roles were made as androgynous as possible so that they could be cast as either men or women as the casting director saw fit. Taking the above into account, if things had gone differently, this trope could very well have been played straight.)
There is evidence that both Jangle Leg and Biscuit in the movie Life are only together due to long prison terms and this trope. Jangle Leg is shown to be attracted to women (when they're around) and Biscuit can't bear to go home to his mom "like this", implying that he wasn't always gay (and flamboyant.)
In the Discworld series of books, dwarves embody this through most of the series. Both male and female dwarves wear the same clothes, have beards and so forth. Therefore, courtship for dwarves is described as delicately finding out the sex of a fellow dwarf. This starts to change through one female dwarf taking on Tertiary Sexual Characteristics and identifying as female, causing a large uproar in the dwarven community.
Rather baselessly averted in John Wyndham's Consider Her Ways. In the aftermath of a virus wiping out all men, a basically sexless society emerges. Wyndham seems to have utterly dismissed the possibility that women could form romantic relationships with each other, despite making a reference to Sappho at one point. He admitted that he put plot ahead of common sense in that one and seemed to regret it. Happens to the best of us.
The Thin Red Line (the James Jones book that Terrence Malick's famous film is based on) discusses this notion and has several examples among its cast of characters.
The Wheel of Time has what are euphemistically referred to as "pillow friends", especially among initiates in the White Tower, where girls are isolated from men (and the world altogether) and would have problems anyway due to their powers and extended lifespan. Treated as a very private matter and not looked down upon, most of these relationships dissolve upon completing the long training process, anyway, though not always. All of the all-female organizations have some mention of this. Complicated by the fact that "pillow friends" can refer to a platonic friendship, since sharing a bed isn't always sexual—it's just as often that one of the friends has been punished and wants to cry herself to sleep on a friend's shoulder.
A comparably extremely brief allusion to a male equivalent in The Empire's military companies occurs in Knife of Dreams during Tuon's point-of-view.
In Tanya Huff's Enchantment Emporium the Gale clan usually keeps things in the family and there are more female Gales than male so they tend, in the words of one of them, to be "enthusiastically undiscriminating".
The planet Athos in the Vorkosigan Saga. Originally founded as a "monastery planet" by a religious cult who believed that women were the cause of all male sin, it has since evolved into a society where most men pursue non-religious professions. Reproduction is accomplished via Uterine Replicator technology. However, their religious culture forbids even depictions of women and censors all Galactic media. Thus most Athosian men will never even see a woman, nor have their ancestors going back generations. Homosexual relationships are therefore the norm, although some men, implied to be strongly heterosexual, remain celibate instead.
Tony: Well, what are you gonna do? There's no women there! You're there five, ten years! (Beat) Just for the record, my incarceration was very short term, so I never had any need for any anal— you know. (...) You think I'm lying, don't you?
T-Bag on Prison Break was very interested in his fellow male prisoners while behind bars, but as soon as he got out he seemed far more interested in women.
If this isn't what Elvis Presley's "Jailhouse Rock" is about, then what the hell is it about?
Number forty-seven said to number three:
"You're the cutest jailbird I ever did see.
I sure would be delighted with your company,
come on and do the Jailhouse Rock with me."
The writers (and by their account Elvis himself) knew this was a gay line and thought it would be funny to put it in and see what happened. They said they put in lots of stuff like that, because they knew Elvis wouldn't have a problem with it.
Can be Truth in Television; the old Royal Navy was famously rife with "rum, sodomy, and the lash", and not all prison sex is Prison Rape. Until anti-sodomy laws were struck down in Britain, the only time that "buggery" was legal was "after ninety days at sea," at which point it was no longer a crime.
As The Onion blurb in Our Dumb Century for August 15th, 1954 put it: "Let's Work Together to Pretend Our War-Time Homosexual Experiences Never Happened".
Old joke about life on submarines, "150 people go down, 75 couples come up"
Hence the phrase "Prison Gay", with the con asserting, despite the evidence, "I'm not gay"
Parthenogenesis: essentially, the female's eggs contain both X chromosomes. There are several species of lizards that ONLY produce offspring this way (no males). In fact, one female will mount another, which increases fertility.
Others, due to the way that reptilian genetics can work, produce only males through this method.
Plus bison and other animals with sex-segregated herds. You can only go so long without!
While in heat, female rats and mice will often start humping each other in the absence of males. Ahem...
A lot of people in the porn business. Both male and female.
World of Warcraft and indeed the entire Warcraft lore makes it fairly clear that all male Night Elves went into the Emerald Dream, while the females stayed in the material world. For several thousand years. Even after the awakening of the males, and the destruction of the world tree stripping the Night Elves of their immortality, there are hints and fluff pointing to this trope being in effect for the females at the very least.
This, with a side order of Prison Rape, is how Enzai justifies its sheer number of possible homosexual encounters. What makes it all the more cruel is that the protagonist is genuinely gay.
Toyed with in the No Fourth Wall webcomic 1/0. Marcus, existing in a world consisting of only male characters, has no concept of women and tries to flirt with the guys instead. Tailsteak clarifies that Marcus isn't gay, "he's just settling for second best," then introduces a female character to clear things up for Marcus. (Said female character is gay, just to annoy the cast.)
Thief and Fighter have a little discussion about this and elven prisons in 8-Bit Theater.
The presence of romance in most Transformers continuities combined with the fact that about 90% or more of the Transformer population is male leads to the insinuation that many Transformer romantic relationships must be male/male by default. The canon doesn't help.At all.
And on the other gender of that age demographic, most My Little Pony shipping is between females, because of similar logic.*
Male characters are often shipped with other males, but that might be for a different reason.
Partially averted in Friendship is Magic...where there ARE at least a decent amount of male/female shipping in fanfics.
Subverted in the Family Guy episode "Perfect Castaway". Peter is stranded on an island with Quagmire, Joe, and Cleveland. Noting that there are no women and men have needs, he says they need to have an orgy. Cut to a shot of them piled on top of each other...and no one is horny.
Atlantis in Ugly Americans turns out to be an entire Underwater City of this. Women don't have enough testosterone to survive the pressure down there, so they make do.