Aliens Made Them Do It

"Last time aliens invaded all they did was force the most intelligent of us to pair off and mate continuously... Oh, yes..."

- Professor Hubert Farnsworth, Futurama, applying an Anticipatory Breath Spray.

Aliens Made Them Do It is a specific kind of shipping trope often used in fanfics to get two characters who have little motivation to have sex to do so - as such, it's a standby of Slash Fic and Crack Pairings of characters who hate each other.

In the most traditional use of this trope, aliens kidnap the characters and require them to have sex for scientific study or experimental purpose. The trope's meaning widened to include any case where an external force contrives, orders or forces the characters to have sex for its own purpose - a bit of Applied Phlebotinum may or may not be employed to grease the wheels. The trope is parodied as often as it is used straight, and may lead to a Mister Seahorse instance (often justified by alien technology).

A variety of Deus Sex Machina, and an extreme case of Kissing Under the Influence. Compare with Mate or Die.

Anime and Manga

 * A tame example is found in Super Dimension Fortress Macross/Robotech, where the Zentraedi force Misa/Lisa and Hikaru/Rick to kiss.
 * There's a joke about it in the Robotech Novelization about it: judging by the Zentraedi's response, if they had shown them what sex was, it probably would've ended the war right then.
 * The scene is parodied in a Super Robot Wars Alpha 4koma, where Boss and Dr. Hell from Mazinger Z (and Great Mazinger) are amongst the people kidnapped.
 * Deconstructed in Blue Drop: Tenshitachi no Bokura, in which the main character must have sex with a certain girl, who is actually, in a week, or else evil lesbian aliens will kill them both. Needless to say, neither of them want to have sex, and are in fact disgusted by the idea. It gets worse for them from there.
 * The doujin U.F.O. by Naruko Hanaharu has aliens abducting two humans from Earth shortly before it is destroyed; the girl is forced to choose between this and artificial insemination.

Comic Books

 * In John Ridley's comic miniseries The American Way, it's suggested that to take everyone's mind off a recent tragedy, two superheroes should go on a high-profile dinner date. The woman of the pair is quite forceful, and suggests something to the man (who has a reporter girlfriend) that results in them beating the crap out of one another in the sky over the restaurant, and refusing to talk to each other ever again. The government feeds the papers this trope as the "official" explanation.
 * Johnny the Homicidal Maniac plays this for laughs in one of the "Meanwhiles", when a pair of aliens abduct a store manager and force him to have sex with one of the "females" of his species... which, according to them is a chicken. After much arguing and threats, he finally gives in - a flash-forward at the end shows him with human-chicken hybrid children, saying "And that's how I met your mother."
 * In Justin Green's classic Binky Brown Meets the Holy Virgin Mary, the parochial school teen Binky Brown imagines that "bad men" have tied him and his latest crush together and are forcing them to have sex.
 * DC Comics:
 * The infamous storyline in Action Comics Vol. 1 issues #592-593 where Superman and Big Barda are forced to film a porno by the Depraved Dwarf Sleez, only for Mister Miracle to (thankfully) interfere before they went too far.
 * Sleez orchestrated the kidnapping of Big Barda using the theft of her Mega-Rod, and mind-controlled her into sexual servitude, even filming some of it. Superman had been tracking an energy signature from the Rod that led him to the pair; he threw Sleez into a wall, only to be attacked and nearly killed by the traumatized Barda, who thought he was another pawn in Sleez's scheme. This leads to Sleez gaining control over them both - Superman was able to partly resist Sleez's mind control, albeit "only" to the extent that the director commented that his performance wasn't very enthusiastic. Meanwhile, Darkseid of all people shows Mister Miracle a tape of Big Barda Sleez had filmed (no guesses what it contained) that his agents had intercepted, leading to Scott searching for his wife and breaking up the porno shoot, freeing them of the mind control. Superman then pursues Sleez into the sewers, where he blows them (and himself) up. Thank you, John Byrne.
 * For what it's worth, Sleez's origins (by his own account, mind) place him as a former aide to Darkseid who was banished to Earth for being too depraved and vile.
 * Cracked.com lists this as #5 in this article of "5 Creepiest Sex Scenes in Comics".
 * Happens in one Titans issue. The formerly-engaged Starfire and Nightwing are searching an abandoned building when they suddenly decide to have a quickie for old time's sake - shortly afterward, they realize how unprofessional, if not out of character, that was for them. It all starts to make sense when they realize their target was one of seven demons, each of whom is an incarnation of one of the Seven Deadly Sins. No points for guessing the sin their quarry represented.
 * In an issue of Outsiders, a Russian gangster gets the powers of the demon Sabbac (an Evil Counterpart of Captain Marvel, whose name is an acronym of the names of demons the way "Shazam" is an acronym of the names of gods) which includes control over the Seven Deadly Sins. He attacks a prison and makes all the inmates and guards have an orgy, then makes his lackeys - the four surviving members of the Fearsome Five - have sex with each other. Specifically, he pairs off Psimon and Shimmer, and Jinx and Mammoth, then threatens "Don't complain, or I'll have everyone switch partners. Which means either Mammoth will be banging his sister or you'll all be having the gay sex." When the Outsiders show up to fight him, he threatens to use his lust power on Starfire to "see if the carpet matches the drapes."
 * Mystical forces made do it in the "Twilight" arc of Buffy the Vampire Slayer Season Eight.
 * In New Mutants, Empath breaks into Xavier's School, but is caught off-guard by Tom and Sharon; he uses his emotion-controlling power to make them have days of uninterrupted, kinky sex instead of alerting the staff and students. It's Played for Drama, as they are pretty much written like rape victims afterwards, and any kind of romantic tension which could have existed between them is dead for good.
 * Empowered parodies this in a Show Within a Show Slash Fic Emps reads about her teammates.

Fan Works

 * In the Warcraft fanfic Ethereum Gladiator, this trope is reconstructed something fierce.
 * Uncannily common for the Snape/Harry ship in the Harry Potter fandom. In general, fandom plots revolving around an accidental or forced bond tend to use powerful charms, curses and Love Potions that have similar effects to this trope. This unfortunately draws from canon: was conceived while his father was under the effects of a Love Potion.
 * In DCU fan works (primarily Batman ones), "sex pollen" created by villainess Poison Ivy is used for this trope.
 * In DC Nation, a really bad leftover Poison Ivy/Flash ship is retooled into an actual plot point: The "Brain Spores" that took over Wally West were a form of sentient plant that Ivy realized too late would have been a perfect mate, and it's been used as a motivator for Ivy and a source of headaches for Wally since.
 * Techically a demigod made them do it, but in an extremely NSFW fan comic by Sharpie, the ladies can't keep their hands off of Superman.
 * Doctor Who:
 * 'Alien sex pollen' generally tends to show up in fanfiction for similar purposes, though there are just as many fics mocking it for being an overused cliche.
 * One Fourth Doctor/Sarah Jane fanfic has aliens kidnapping the characters and forcing them to mate in the traditional fashion. Only afterwards did the Doctor point out that being aliens, they wouldn't have known the difference if the Doctor and Sarah decided to shake hands instead.
 * Stargate Atlantis:
 * Parodied in this fic from LiveJournal titled "Minion of the Universe".
 * Even more delightfully inverted in another fic titled "Abstain".
 * This The Hitchhiker's Guide to the Galaxy fanfic, titled "Aliens Make Ford and Arthur Have Sex''. It is followed by sequels in which Mister Seahorse occurs, justified as much by alien technology as it is because it's funny.
 * So common on the Star Trek fandom's kink meme that it has its own tag.
 * Nearly happens in the "Charity" episode of the Firefly fic Forward, involving . The actual reasoning is complicated: They're protecting a group of refugees, but . In this case, . It is only stopped when.
 * In Ranma ½ fanfic, there's the fanonical "passion spice", a Chinese Amazon drug which acts as a super-aphrodisiac.

Film

 * In Colossus: The Forbin Project, Dr. Forbin convinces Colossus that he is having an affair with one of his assistants as a means of gaining privacy for planning how to deactivate the computer.
 * The eponymous cologne in Perfume smelled so good, it forced a whole village square to erupt in a free-for-all orgy.

Literature

 * In the Isaac Asimov short story "What is This Thing Called Love?", a pair of mono-gendered aliens abduct a man and a woman in order to study human sexuality, since the aliens themselves and every other species they've encountered to that point reproduce asexually. One of the aliens is a scientist who has started to figure out the "One species, two genders" concept, but the other is an officer who cannot wrap its mind around such a thing, and is disturbed by the very notion; nonetheless, they try to get the two disturbed and offended strangers to mate. Fortunately, the captain cut the entire experiment short after their reluctant first kiss: much of the scientist's information about human sexuality came from racy-but-non-explicit pulp fiction. After their release, it was only natural that the man and woman spend a few minutes talking about the affair, head inside for a drink, and then... Unfortunately for the alien scientist, their ship leaves the planet just as it notices this, and the captain never looks at the screen to see what it is so excited about.
 * In E. E. "Doc" Smith's Lensman books, the super-advanced Arisians are slowly breeding the ultimate humans by subtly encouraging the best and brightest to marry and have children. As a reversal of the trope, the Arisians also make sure the two star lines do not mate before the proper time by ensuring that the opposite-gender members of each line dislike each other the closer they get - as humans are chosen to be the Children of the Lens, three other species who also have star lines are never allowed to mate and achieve their race's true potential.
 * Kurt Vonnegut's novel Slaughterhouse-Five involves the scrawny main character and a porn star being abducted by aliens. While the aliens didn't force them to mate, they expected it to happen sooner or later, and put them together for the rest of their lives in the same house/cage as the only two humans on their planet. While still unclothed, of course.
 * Harry Turtledove's Alternate History series Worldwar dabbles in this a fair bit.
 * Scientists of The Race (aka the Lizards) are so shocked to discover that humans don't have a mating season, they take several of their human prisoners aboard ship and force them to 'go screw' with random members of the opposite sex. They are even more shocked when some of these humans 'form permanent pair bonds' (i.e. fall in love), an idea that they meet with a mix of amusement and disgust.
 * Back in the original series, one of these couples - Liu Han and Bobby Fior - are later brought back to Liu's native China when Han becomes pregnant. The experiment isn't quite over, however: after she gives birth, they take her daughter Liu Min back up to the research ship to see if they can raise a human as a citizen of the Empire. Han, who is now alone after Bobby's heroic but rather pointless death, joins a Maoist resistance cell in a bid to regain her; she eventually succeeds, despite the rather petty attempts of the Lizards to discredit her (by showing footage of the 'experiments' in public!), but she and later Min remain with the PLA, eventually become an important member of the People's Revolutionary Committee.
 * The Race even fall victim to it themselves: when the all-male colonization fleet arrives, they find to their chagrin that the powerful Earth narcotic 'ginger' has the side effect of causing females to go into season immediately. They end up sheepishly asking their human advisers for advice on how to deal with the inevitable changes this brings to their society among the Earth/Tosev-3 colonists.
 * A running plot element in the Dragonriders of Pern series: When dragons mate, their riders will be compelled to mate with each other regardless of gender. Even those riders whose dragons weren't successful in catching the female will be overwhelmed with lust - see Jaxom going caveman on his holder girl paramour in The White Dragon. The matings of fire lizards, tiny creatures related to the larger dragons, are shown to have a similar but much milder effect. However, the lust seems to be compelling only if there was pre-existing sexual attraction between the parties.
 * A mating dragon is also known to spread the need around to anyone they happen to fly over, though only the riders of the dragons involved are forced to comply - it's implied that the Weyrfolk have no problem with this phenomenon, though, and it's a major reason for their more open attitude towards sex in general, as green dragons are the most common type and frequently are known to be in rut.
 * The extreme cold of Between, an inter-dimensional space dragons can cross, is highly likely to terminate any first-stage pregnancies that might result from the above. Those who know they're pregnant avoid going between at all costs; it's also implied that it's used as form of abortion - while officially frowned upon, most Weyrleaders and Lord Holders look the other way. According to Kylara in Dragonquest, it takes an "extra moment between" to cause an abortion; other books indicated that repeated trips harm Lessa's ability to have children.
 * In one short story, an alien charged with overseeing the Earth did this to everyone on the planet at once via Mind Control to stop them from starting a nuclear war. It worked until.
 * A very dark example in Robert Silverberg's Passengers. The Earth has been invaded by disembodied intelligences with a taste for controlling individual humans - this trope is one of the nicer things they do to their victims.
 * Older Than Steam: In Cyrano de Bergerac's Voyage dans la lune, the Selenites capture the hero and treat him like a pet. The Moon Queen already has a human, and the Moon King is convinced that the hero is a female, and that they must mate. As they said, "the prince's will was thoroughly carried out".
 * In Kushiels Scion, mild mannered baron what's-his-name is possessed by his great-grandfather, transforming him into the legendary CAPTAIN SCOURGE, undefeated strategist, unrelenting swordsman, raider and murderer, in his epic struggle to utterly pulverize the enemy monster! Guess what he does to the baron's cousin.
 * This seems to be a theme of the short stories in the universe of The Dresden Files, since it gives Butcher a convenient excuse to put Dresden and Murphy in various positions ranging from hilariously awkward to hilariously fanservice-y.
 * One short story has this occur due to a spell cast by a Red Court vampire as a weapon against the White Court vampires, who are Allergic to Love. Results varied from cute to squicky . The Red Court vampire tries to convince Harry that she's artificially creating love that's as good as the natural thing, but he doesn't buy it.
 * In another side story, magically spiked alcohol from one of Dionysus's Maenads causes people to go into something between a rampage and an orgy. They had no memories of it, and the magical spike was very cleverly designed such that anyone who examined it directly would be affected as if they'd drank it.
 * From the very first book: don't let Bob talk you into making a romance potion. And if you do, certainly don't forget to label it distinctly, such that, say, if you're fighting a demon that suddenly invaded your home and send your girlfriend to fetch a potion of escape, she should be able to tell the two apart. Because wouldn't that have been an awkward series of mistakes to make?
 * Mind Magic like this is very, very illegal in the Dresdenverse. "Laws of Magic" illegal. Death-by-decapitation on suspicion illegal. Guess what one of Harry's apprentice's specialties is?

Live-Action TV

 * Buffy the Vampire Slayer had a house that used Buffy-Riley sex as a battery for its haunted hijinks. After they are "rescued" and the haunting defeated, someone comments on how terrible the ordeal must have been for them. Buffy and Riley meekly "agree" while giving each other meaningful glances.
 * Angel:
 * This almost happened between Angel and Cordelia, when they were both possessed by the ghosts of two lovers stuck in a Groundhog Day Loop. Notably, they actually induced the possession at one point so they could figure out what exactly was going on, but felt rather awkward when it went farther than they expected.
 * Later on, Lorne's empathic powers were malfunctioning, which caused everything he said to be taken as a psychic command, so the alien making Angel and Eve do it didn't even know what he was doing at the time.
 * Star Trek: The Original Series:
 * When Kirk and Uhura performed one of television's first interracial kisses (though not the very first, as is commonly claimed - that was Sammy Davis, Jr. and Nancy Sinatra on Movin' With Nancy), it was because Aliens Made Them Do It. Literally. People still complained, even if the director cut away before actually showing their lips meet. Nichelle Nichols says that the network made them shoot the scene with and without the kiss, and Shatner deliberately screwed up all the "without" takes to force them to show the kiss anyway.
 * Heck, this was the entire focus of the original pilot, "The Cage": the Master of Illusion Talosians telepathically put Pike and Vina into a variety of settings, hoping they'd tumble into each other's arms and begin the process of repopulating the planet.
 * In an episode of Star Trek: Deep Space Nine, Weyoun orders that Worf and Ezri Dax be put in the same cell; he doesn't plan to force anything, but reckons it would be fascinating to watch if anything did happen. Unfortunately for Weyoun, Worf didn't find this very funny.
 * Star Trek: Voyager does it twice with Tom Paris and B'Elanna Torres:
 * In "Blood Fever", Torres' mating instinct is triggered by an accidental telepathic link with a Vulcan undergoing pon farr. It doesn't get consummated, but Paris hints at being interested afterward.
 * In "Scientific Method", after a lengthy Belligerent Sexual Tension courting, Torres suddenly declares that she loves Paris. Pretty soon, they're having passionate sex in not-so-private places (while on duty) at the drop of a hyperspanner, so much so that Captain Janeway has to reprimand them. It later turns out that invisible aliens have been on Voyager for some time running experiments on the crew. Afterwards, the two wonder if their entire relationship is due to aliens tweaking their hormones into overdrive. "Thank God we found out in time," they say (while kissing passionately).
 * Nagilum, the Sufficiently Advanced Alien antagonist of the TNG episode "Where Silence Has Lease", wants to observe the propagation of the species for curiosity's sake. Dr. Pulaski refuses to comply.
 * Blake's 7 did this twice:
 * Tarrant and Dayna narrowly avoid being forced to have one off to satisfy the scientific curiosity of the Ultra in "Ultraworld".
 * In "Sand", Tarrant and Servalan come very close to reproducing to satisfy some intelligent sand that likes killing people (and Foe Yay, apparently), and therefore needs more people around to kill.
 * Almost but not quite three times, if you count the episode "Moloch": the "computer" decision on Servalan's punishment is to "give her to your men", and she winds up being "given" to Vila.
 * La Femme Nikita: In Episode 6, "Love", the evil government conspiracy forces Nikita and Michael of undercover as a married couple, under the watchful eye of a voyeuristic terrorist. Naturally, they simply must keep up their cover. Supposedly, the episode was specifically written to subvert fan demand for Nikita and Michael to get together.
 * Red Dwarf also features this. A Psiren (not technically an alien as it's from Earth, one of the staples of the series) uses an illusion to make out with Lister, although it turns into a huge dung-beetle before they can copulate and attempts to suck out Lister's brain.
 * True Blood had Maryann, who enchanted the whole town into a hedonistic orgy.
 * Torchwood briefly features Owen using salvaged alien tech to do this.
 * On The 4400, Lily and Richard slowly discover that somehow, they conceived a child together during the time they were abducted. They had never met before their abductions (Lily had not even been born when Richard was taken) and had no memory of what went on during that time. It is never fully explained whether they had a romance they now could not remember, or had been part of an alien breeding experiment. It is shown that Lily's grandmother and Richard were a couple before Richard's abduction, suggesting perhaps that their abductors thought Lily was close enough to a woman Richard had previously been attracted to.
 * Steven Spielberg's Taken miniseries had a literal case, where the two parties were taken aboard an alien spaceship to breed with each other.

Video Games

 * Subverted in Persona 3, where one of the boss battles in takes place inside a Love Hotel. After defeating the first Shadow, the party is Brainwashed by a second, hidden Shadow, but manage to break free from the mind control before things go too far. The game does not give you the option of actually giving in.
 * During Final Fantasy VII, the mad doctor Hojo places Red XIII and Aeris in the same cell, since they are both presumedly the last of their species, and he hopes to mate them. He doesn't take into consideration the fact that Red XIII is a quadrupedal lion-like creature while Aeris is, for all intents and purposes, a human. Needless to say, no mating of any kind occurred.
 * A Manipulative Bastard mage (arguably the Big Bad) in Fire Emblem Jugdral brainwashes a noble and his half-sister into breeding a new vessel for a dark god.
 * In the X-rated visual novel Euphoria, the characters awaken in a mysterious windowless room and are forced into a sadistic "game" where they have to comply with the (primarily sexual) orders of a disembodied voice under pain of death.

Web Comics

 * In Platinum Grit, aliens arrive to try and help a mortally embarrassed Jeremy sleep with a rather bemused Nils. This keeps everyone busy for two whole issues, and naturally.
 * Discussed by two aliens in this Saturday Morning Breakfast Cereal. Their process involves ghostwriting letters to convince the woman that the man is worthy of her respect in trust, whereas the man must only be directed towards the woman's breasts.
 * In a small General Protection Fault story arc, aliens don't technically force Fooker and Trudy, but wouldn't let them go until they did. However, Trudy managed to talk her way out of it.

Web Original

 * Played For Laughs in Dragonball Z Abridged: Nappa (a Saiyan) forces the king of the Bug People to have sex with his wife. Vegeta finds this very disturbing, enough that he destroys the planet out of spite.

Western Animation

 * Futurama:
 * The source of the page quote above, which has Farnsworth recounting a Noodle Incident involving this.
 * In another episode, Zapp attempts to fool Leela into believing an Adam and Eve Plot is taking place, which is the only way the man could ever score with her again (he used up the pity card the first time). Though Leela figures out what he's up to, a Death Star-like censorship satellite demands that they copulate, since it sees said plot as one of the few good things about humanity. Leela is a good sport and takes one for the team, but Zapp didn't enjoy having an "audience" - and Fry did not enjoy being the audience.
 * In one Treehouse of Horror episode on The Simpsons, Maggie turned out to be the result of Kang impregnating Marge. The whole thing was Played for Laughs: the aliens provide Marge with several backdrops, like the backseat of a car and the alley behind a porno theater; there's also a moment where the insemination is done via ray gun, and Kang gets offended when Marge says "That was quick".