History Main / AccidentalAdultery

* In ''Film/PearlHarbor'', Rafe is presumed dead after being shot down over Nazi Germany. His {{Love Interest|s}} Evelyn begins a romance with his best friend Danny, which makes things awkward when Rafe returns alive. Fortunately, Danny has the good manners to get himself ''actually'' killed on their next mission, leaving both of them SomeoneToRememberHimBy.
* In ''Film/CastAway'', Chuck's fiancée Kelly says that she "always knew" he was alive, but felt she had to let him go, and [[AbsenceMakesTheHeartGoYonder married a dentist]]. [[spoiler: She offers to divorce her new husband to get back together with Chuck, but he doesn't want to break up her new family.]]

* The main character of ''Film/RandomHarvest'' is an amnesiac who, oblivious to the fact that he is already married, becomes engaged to a young admirer. His wife tracks him down and [[AmnesiacLover attempts to trigger his memories of her]]; his new fiancée [[IWantMyBelovedToBeHappy breaks off the engagement]] [[AvertedTrope before this trope can take full effect]].

* {{Averted|Trope}} in ''Literature/TheOdyssey''; presumed-widow Penelope has no shortage of suitors-- some [[YouHaveWaitedLongEnough quite forceful]]-- while presumed-dead Odysseus is LostAtSea, but she stays faithful for ten years. More faithful than Odysseus himself, for that matter, although "[[QuestionableConsent he never gave consent in his heart]]" and saying 'no' to goddesses was a good way of making sure he ''never'' got home.
* ''Literature/TheLostFleet'': Towards the middle of the original series, [[spoiler:Rione, who has been sleeping with Captain Geary up to this point,]] discovers that her husband might actually be alive and kept as a prisoner of war. This causes her to immediately break off her current relationship, which was already a FriendsWithBenefits situation at best. A few volumes later said husband actually turns up, and... Well, suffice to say he didn't take it very well when he found out. In the end, though, [[spoiler:Rione chooses to die at her husband's side, whose mind has already been warped by the secret government experiments, while saving everyone else in the process]].

* In Creator/HarryTurtledove's ''Literature/{{Worldwar}}'' books, Jens Larssen (a nuclear physicist with the Manhattan Project) gets sent on a cross-country trip to deliver an important message under the radar of the invading aliens. In the meantime, his wife Barbara strikes up an entirely platonic friendship with soldier Sam Yeager. However, Barbara and Sam end up having GladToBeAliveSex after surviving an alien attack (something they're both deeply ashamed of afterwards), and a short while later Jens is presumed dead when his destination is blown up, which leads to the pair forming a romantic relationship and getting married. In reality, Jens was in the hands of the US Army, and the commanders refused to let him send any letters to Barbara because it would risk compromising him. When he does make it back, Barbara is pregnant with Sam's child and ultimately stays with him; Jens resolves the LoveTriangle by deciding to betray humanity to the aliens as payback for all the indignities he'd suffered and getting killed in the process.
* In ''Literature/TheScarletLetter'', Hester is separated from her husband, and believes him to be dead. While she's grieving, she's [[ComfortingTheWidow comforted by Rev. Dimmesdale, in more ways than one]]. She becomes pregnant by him, which is a big taboo in their Puritan society. To add insult to injury, she finds out that her husband was ''not'' dead. She is estranged from him for the rest of the story, though her husband is understanding, more concerned with finding out who her child's father is than trying to punish her. It's really ''Dimmesdale'' he wants revenge on. The main reason why Chillingsworth does not seek revenge on Hester was because he was an older man with an implied case of scoliosis (one shoulder slightly higher than the other), and he married Hester despite knowing that she didn’t love him.
* In the ''Literature/SherlockHolmes'' short story "The Adventure of the Noble Bachelor", the titular character's young bride disappears because [[spoiler:her husband, whom she had given up for dead, turned up alive at the wedding]].
* In ''Literature/LegendsOfDune'', Serena Butler is engaged to Xavier Harkonnen during humanity's desperate struggle against the [[AIIsACrapshoot Thinking Machines]]. During a trip to another planet, her ship is captured by the machines, who take her to {{Earth|ThatUsedToBeBetter}}, where independent robot Erasmus expresses an interest in her fierce personality, wishing to study her further. Back on Salusa Secundus, everyone assumes Serena is dead, and the grief-stricken Xavier ends up [[ComfortingTheWidow finding comfort in the arms of]] Serena's sister Octa (who has long had a crush on her big sister's fiancé), eventually marrying her and having several children. Serena turns out to be pregnant by Xavier and gives birth. After a while, [[spoiler:Erasmus gets fed up with the baby's crying and constant need for attention from his research subject, so he casually throws the child off a high balcony, inadvertently inspiring the human slaves on Earth to revolt, kickstarting the Butlerian Jihad]]. After Serena returns to Salusa Secundus, she is deeply hurt by finding out that Xavier has moved on, but understands why he thought she was dead. This is one of the reasons why she ends devoting herself to the Butlerian Jihad and [[spoiler:willingly sacrificing herself]] in order to inspire the people to destroy the Thinking Machines.

%% * In a variant, ''Literature/WeCantRewind'' has a case of accidental ''fornication'' due to a FreakyFridayFlip leading to certain erroneous assumptions concerning identities. [[spoiler: The step-siblings Jackie and Jaymee assume that being in their married parents' bodies means they ''are'' their parents, and therefore they are married. Upon discovering this, their parents immediately scold them and set them straight.]]

* In ''Series/StarTrekDeepSpaceNine'', Odo gets involved with an informant he's protecting. Turns out, she's an undercover agent for a government that uses EasyAmnesia and FakeMemories to ensure their agents believe their own covers, making them virtually impossible to detect. When her mission is complete, her original memories are restored, and it turns out she's married. She takes it in stride, having known the risks of the mission. Odo seems to take it much harder.
* At the start of ''Series/StarTrekVoyager'', Captain Janeway is engaged to a civilian named Mark Johnson when the titular ship becomes stranded on the other side of the galaxy. Mark eventually marries someone else, which Janeway finds out when Starfleet reestablishes contact with ''Voyager'' in "[[Recap/StarTrekVoyagerS4E14Hunters Hunters]]", 14 months after the ship went missing in action and she was declared LegallyDead. What ''really'' stings about this is that she'd still been holding out for him all this time, passing up a possible romance with her first officer Chakotay and an offer from Q to transport her ship home in exchange for having a baby with him, among other things.
* Karen on ''Series/WillAndGrace'' starts up a relationship with another man after her husband Stan supposedly dies. Stan later turns out to have faked his death, but Karen has already divorced her new husband by this time. (In fact, she requests a divorce during the ''wedding reception''.)
* One case on ''Series/NightCourt'' concerns a Vietnam veteran who went MIA and eventually came home to find his wife remarried. This proves to be a hard choice for the wife because she loves both of her husbands. Later, husband #1 saves husband #2 from choking and decides to move on.

* In ''Series/{{Eureka}}'', Allison ends up accidentally getting launch along with the actual crew of the ''Astraeus''. They finds themselves back at Eureka but are told that 4 years have passed since their departure. To her horror, Allison finds out that Jack is now with Jo, having thought her dead, and has no intention of getting back with her. [[spoiler:This turns out to be not true, as the crew is actually stuck in a virtual reality world created by the Consortium.]]
* In ''Series/GossipGirl'', Serena tricks Dan into believing that Blair dumped him, so he would cheat on her. This turns out to be true, but since Serena didn't know it is a case of manipulating into sex and, therefore, accidental adultery.

* ''Series/TheBoldAndTheBeautiful'': Ridge Forrester sleeps with ex-girlfriend Morgan, who has asked him to father her baby, believing that he has permission from wife Taylor to do so. It turns out that Morgan faked the permissive e-mail that Taylor supposedly sent.
** Also, during a masked ball, Brooke thinks she has enticed Ridge into some WallBangHer sex. It turns out that the man in question was her daughter's boyfriend, making her play this trope twice.
* ''Series/AllMyChildren''. Doped up on pain medication, Erica throws herself at her doctor. Not until she calls him by her husband's name do either of them realize what's happened.
* ''Series/SunsetBeach''. Ben's evil twin Derek takes his place in his life and soon seduces his fiancee Meg, basically raping her as she believes it's Ben she's making love to.
* A "ReportsOfMyDeathWereGreatlyExaggerated" version occurs on ''Series/AmericanHorrorStoryAsylum''. Kit Walker, committed to the criminally insane asylum for the supposed murder of his wife Alma, falls for another inmate, Grace Bertrand, and has a romantic and sexual relationship with her. Upon his release, he takes Grace home, to discover [[spoiler:Alma alive and well; she had been abducted by aliens and returned years later.]].
* In ''[[Series/AltaMar High Seas]]'', Nicolás falls deeply in love with Eva, only [[spoiler:for a telegram to arrive that his wife Chantal, whom he thought long dead (she was captured by the Nazis in France), is alive and waiting for him]]. He tells Eva about it, and she is understanding and lets him decide what to do. Ultimately, it seems he has chosen Eva [[spoiler:and plans to gently explain everything to Chantal. As of the second season's finale, he is last seen just when he meets his wife]].
* ''Series/TheBrittasEmpire'': The episode "Temple Of The Body" reveals at the end that Brittas had sex with Carole under the belief that he was bedding his wife Helen (it was a costume party and they were wearing the same tiger costume). This becomes an issue when Carole falls pregnant from the encounter (though neither find out until the very end of the series).
* In ''Series/{{Manifest}}'', this is one of the problems the passengers have to face. After the plane's disappearance, many of their spouses and significant others assumed the obvious and moved on with their lives. Cue much awkwardness when the plane actually arrives five years later, which to the passengers was just a few hours.

* The French song "Brave Marin" is about a sailor who goes into a bar and starts drinking and singing, while the bar's owner starts crying. He asks her why, she says he reminds him of her dead husband. He then notes how many more children she has (it can be anywhere from three to ''twelve'' depending on the version). She's received so many letters saying he was dead that she remarried. [[DownerEnding The sailor finishes his glass and goes back to his ship.]]

* During Jane's wedding in ''WesternAnimation/CampLazlo'' it's revealed her fiancee Manfred has several wives already. When confronted about this, he points out he doesn't remember being married but his memory is fading so it's very likely he already is.

* In ''VideoGame/{{Catherine}}'' the protagonist Vincent wakes up from a night out with his friends with a younger blond woman named Catherine in his bed. He has no memory of how she got there, but he knows his girlfriend Katherine won't be happy. [[spoiler:It turns out that she was a succubus sent by Thomas Mutton, AKA the Dumuzid, to seduce him and many other males, forcing them to fall into the Trials (ironically, however, she isn't actually sleeping with most of them, Vincent included). Depending on the ending, Vincent either manages to patch things up with Katherine due to the fact that the nature of the encounters (Catherine never appears to anyone else other than who she's currently seducing, meaning the whole thing comes off as made-up) being explained as symptoms of stress, or he ends up becoming an Incubus and taking over hell with Catherine.]]

* {{Played With}} in ''WesternAnimation/{{Disenchantment}}.'' After the death of his first wife, Dagmar, Zøg had a [[AltarDiplomacy diplomatic]] but tepid marriage to Oona. However, Dagmar was actually only TakenForGranite and eventually comes back to life. The thing is, Zøg ''knew'' this, actively worked to bring her back, and apparently just...[[DidntThinkThisThrough didn't consider]] that this might create problems with the current queen. In the end, [[spoiler:Oona demands a divorce, even though Dagmar turns out to have been EvilAllAlong and is no longer in the picture. Ironically, Zøg and Oona's relationship actually improves after they split up.]].

* {{Downplayed}} in ''Comicbook/TeenTitans.'' [[Comicbook/{{Superboy}} Kon]] really ''was'' dead for a while, during which his girlfriend, [[Comicbook/{{Wonder Girl}} Cassie]], and best friend, [[Comicbook/{{Robin}} Tim]], started dating. It seems to have been closer to SexForSolace (though they never actually had sex), and the two are kind of freaked out when Kon [[DeathIsCheap inevitably comes back to life]]. Thankfully, [[MilhollandRelationshipMoment he's not upset at all]].
* In ''ComicBook/TheWalkingDead'', main character Rick's wife Lori [[GladToBeAliveSex sleeps with]] best friend Shane when Rick is presumed dead in the ZombieApocalypse. It plays more like standard adultery than most examples of this trope, since it had only been a few days or weeks and they have no evidence for Rick's death beyond, "yo, zombies." When Rick returns, Lori considers it a mistake and wants [[LetUsNeverSpeakOfThisAgain to forget it ever happened]], but Shane [[MurderTheHypotenuse has other ideas]].
* In ''ComicBook/TheUltimates'', Bucky marries ComicBook/CaptainAmerica's fiancée during the latter's long stint as a HumanPopsicle. Considering that Cap emerges still physically in his twenties to find Bucky and his former fiancée as senior citizens, a [[MayDecemberRomance resumed romance]] was unlikely in any case.
* When he thought ComicBook/{{Mockingbird}} was dead, ComicBook/{{Hawkeye}} had a few relationships and one-night stands. She doesn't blame him, and the trope is subverted, since she thought they were separated the entire time (she had been replaced by a [[VoluntaryShapeshifting Skrull]], who reconciled with him and then died a few issues later).

* ''Series/{{Friends}}'' has a famous example of the PoorCommunicationKills variety; during an argument, Rachel tells Ross that they should "take a break... from us". Ross becomes upset and storms out. Rachel's co-worker Mark comes over to help her through the fight, and she makes clear that she doesn't want to break up, but when Ross calls to talk to her, Mark answers the phone. Ross takes this as confirmation that they're broken up, gets drunk, and has a one-night stand. Rachel considers it cheating; Ross [[CatchPhrase repeatedly and vociferously disagrees]].

* A non-sexual version in ''WesternAnimation/StarVsTheForcesOfEvil''. Marco and Star are trapped in a photo booth and share a kiss after the former admits to reciprocating the crush that Star told him she had several months prior, which was what the person who trapped them in there wanted. The problem? Star is currently dating Tom, who views Marco as his best friend to the point that, when Marco does tell him about the incident, he assumes it was a bluff in order to show his loyalty to their friendship. Even after clarifying, Tom is disappointed but still amicable (granted, they had more important issues than a love triangle to deal with at the time).

* {{Played With}} in ''WesternAnimation/{{Disenchantment}}.'' After the death of his first wife, Dagmar, Zøg had a [[AltarDiplomacy diplomatic]] but tepid marriage to Oona. However, Dagmar was actually only TakenForGranite and eventually comes back to life. The thing is, Zøg ''knew'' this, actively worked to bring her back, and apparently just...[[DidntThinkThisThrough didn't consider]] that this might create problems with the current queen. In the end, [[spoiler:Oona demands a divorce, even though Dagmar turns out to have been EvilAllAlong and is no longer in the picture]].

** {{Inverted|Trope}} in the backstory. Dante's girlfriend Caitlin once ''intended'' to cheat on him at a costume party and arranged to meet another guy in a darkened bedroom. She got the wrong bedroom and instead unknowingly had sex with Dante, who was there passed out.

* A husband goes to a costume party dressed as a gorilla, leaving his disapproving WetBlanketSpouse at home. As soon as he leaves, she puts on her own costume and goes to the same party, intent on seeing how faithful he is when unsupervised. When she arrives, she sees her husband chatting up several young ladies (still in costume). She goes up to him comes on to him so strongly that they're having costumed sex five minutes later, after which she leaves the party. When her husband comes back, she asks if he had fun in the most icy tone possible, to which he answers:

'''Whale:''' Katherine?\\

[[folder:Mythology]]

* In Myth/EgyptianMythology (at least [[DependingOnTheWriter in some versions]]), Osiris is murdered because he accidentally sleeps with his wife's twin, Nephthys, who also is his brother Set's wife.

* ''WesternAnimation/PocahontasIIJourneyToANewWorld'' begins with John Smith [[DisneyDeath apparently dying]] while in London. Pocahontas gets word of his death, mourns, and eventually begins to develop feelings for John Rolfe.[[note]]Yeah, [[OneSteveLimit the names]] make it [[ReplacementGoldfish a little weird]], but to be fair [[RealityIsUnrealistic they're both based on real people]].[[/note]] She's a bit torn when she discovers that Smith is alive, but it quickly becomes apparent that they want different things in their lives, and ultimately Rolfe returns with her to Virginia.