History Main / TheMistress

* Wrestling/VinceMcMahon Jr. has had several, the most famous of them being Wrestling/TrishStratus. Stratus did very little to hide her status, thinking herself hot stuff, and part of what made her role famous was a rare feud that had Jr's daughter Wrestling/StephanieMcMahon as a baby {{face}} of [[ALighterShadeOfGrey sorts]] against Trish. The other famous part was when Vince Jr. made it publicly known that Trish was just a toy he was getting bored of, and had her on all fours barking like a dog to keep her job. This had the side effect of [[HeelFaceTurn turning Stratus face]] against the entire [=McMahon=] family, [[FaceHeelDoubleTurn Stephanie included]], ''except'' Vince Jr's wife Linda, who was oddly sympathetic towards Trish in spite of her displeasure with her husband's infidelity. Wrestling/TorrieWilson, [[Wrestling/LisaMarieVaron Victoria]] and Wrestling/CandiceMichelle, the GirlPosse known as Vince's Devils, had the distinction of serving as Vince Jr's mistresses all at once while feuding with a former mistress of Jr's, Trish Stratus. Granted, the feud was over Wrestling/AshleyMassaro asking Stratus for help after weeks being bullied by the three, as well as Stratus having the women's title belt that said Devils ended up [[BackStabbingTheAlphaBitch turning on each other over]]. Still, there was a moment when Michelle had the [[{{hypocrite}} gall]] to call Stratus a {{slut|shaming}}. Ultimately, turning company employees into his mistresses in exchange for benefits proved to be Main/TruthInTelevision for [=McMahon=] and the reason for [[Main/LaserGuidedKarma his downfall]].

* ''Webcomic/MenageA3'' plays with the trope to comedy effect when it turns out that ''both'' Amber and Dillon are playing the mistress to sleazy {{Transparent Closet}}ed bisexual producer Nathan.

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* In ''Literature/FateZero'', Kiritsugu and Maiya have known each other for a long time and have been sleeping together for some time, even after his marriage to Irisviel and despite the fact that Kiritsugu actually loves his wife.
* Akeno takes the place of Issei's Mistress in ''Literature/HighSchoolDXD''. In a twist, TopWife Rias is not only aware of this, but openly condones it, since Akeno is her best friend and Rias knows Akeno has a kink for being the other woman. Even when the rest of Issei's harem eventually marry him and take his name, Akeno never does - it's hard to cheat with your own husband!
* In Yuu Mishouzaki's ''Manga/TheLegendOfZeldaI'' manga, the previous Queen Zelda had an elf lover behind her husband's back. Link is the result of that affair. As her husband was [[FantasticRacism terribly prejuiced]] against elves, the half-elf Link was sent away without knowing his relationship to the Hyrulian royal family.
* ''Manga/MariaNoDanzai'': Mari Nagare/Maria Akeboshi maintains an affair with the principal presumably to keep him under her thumb despite the fact that she clearly detests him and still has feelings for her ex- husband Taiichiro. While in the midst of doing some EarCleaning, when he asks if they could go on a private vacation she deliberately pokes his eardrums.
* Nodoka gets the idea of being this in ''Manga/NegimaMagisterNegiMagi'' when [[DirtyMindReading her subconscious suggests]] a solution to a LoveTriangle she's in. That suggestion is "''saishoudoukin''," a situation where a man keeps a wife and a concubine in the same house.
* ''Anime/Patlabor2TheMovie'': Back when [[spoiler: Shinobu]] was a cadet at the Tsuge Institute, she had an affair with the instructor, himself, despite knowing he was married. It was both a breach of police protocol and ethics. Word of the affair soon got out, reaching as far as he top brass, which created a scandal[[note]]though it isn't said whether Tsuge's wife ever found out he was cheating on her with one of his students[[/note]]. The stigma barred [[spoiler: Shinobu from ever attaining a seat among the higher-ups, which forced her to settle for a position at the SVU]][[note]]Shinobu would have likely gained a position on the Tokyo Metropolitan Police Management Bureau, had it not been for the affair[[/note]].

** When it came to Oscar's father, when a child showed up and claimed he was his son from his late mistress everyone but Oscar's mother believed it because it just made more sense than the opposite - though Andrè's grandmother was ''pissed'' for his infidelity. Eventually it turned out he was the son of a different officer that, when the relationship started, claimed to be the Count of Jarjayes because he felt he wasn't important enough to have that woman as his mistress, and even after being promoted never got around explaining the truth.

* Set in (last years) Victorian England, Count Roland of ''Under The Rose'' manga has two mistresses. One is glamorous, pretty, dughter of [[ImpoverishedPatrician declined Marquis]] Grace King and [[TheDitz clumsy]], [[GirlNextDoor plain jane]] who was [[TeacherStudentRomance his former intern]] Margareth Stanley. It says a lot when each of the mistresses has more active role in children, sans William who is his mother's (legitimate wife) favorite. Yes, it is seinen featuring Disfunctional Family.

* ''Franchise/WonderWoman'' [[ComicBook/WonderWoman1942 Vol 1]]: Lisa Abernathy has been in a long-term secret relationship with the married senator, Brad Covington, who is implied to be her elementary school-aged daughter's father. She is pissed when she realizes Gen. Darnell has figured out that she and Brad are dating.

* "Fanfic/HeisheRinanovai": Morgan t'Thavrau realizes by looking at genetic records recovered from the ruins of Romulus she was conceived as the result of an adulterous affair between [[Recap/StarTrekDeepSpaceNineS06E19InThePaleMoonlight Merken tr'Vreenak]], then a prefectural governor, and his chief of staff Iliana. It's unclear how long the affair went on but Iliana had worked for him for nine years. Morgan surmises her parents ended the affair and kept her paternity a secret to avoid inter-clan blood feuds, never mind a scandal that would've ended both their careers.

* The idea is discussed in ''Fanfic/LostInCamelot'', after Bo (''Series/LostGirl'') forms a triad relationship with Merlin and Morgana (''Series/Merlin2008''). Even after all three accept that they genuinely love each other (Morgana in particular took time to accept the idea that she could have such feelings for another woman), it has been observed that it's unlikely the rest of Camelot will accept the dynamic. Morgana observes at one point that the best they can probably hope for is that Arthur will promote Merlin after he becomes king to a level where it would be publicly acceptable for Merlin to marry Bo or Morgana while the other is his official mistress, and even then such a dynamic wouldn't acknowledge how Bo and Morgana feel about each other.
* Discussed in the ''Film/{{Descendants}}'' series "[[https://archiveofourown.org/series/817440 Package Deal]]", where Mal and Evie were in a relationship back on the Isle of the Lost and thus Evie joins Ben and Mal's relationship after the confrontation with Maleficent. It's noted that Mal is regarded as the "official" royal consort as she was publicly involved with Ben first, with Evie's lesser-known status leading to others referring to her as the king's mistress, but Ben, Mal and Evie all reject that title and affirm that Ben loves Evie just as much as Mal.
* In ''[[Fanfic/{{Restraint}} Aphelion]]'', [[spoiler:Ty Lee]] begins having an affair with [[spoiler:her wife's married brother Zuko]] after [[spoiler:Azula]] runs off because she's scared of emotionally hurting her family. She even ends up pregnant by him. When [[spoiler:Zuko's]] wife finds out, she temporarily leaves with their daughter.
* A lot of the drama in ''Fanfic/MetamorphosisEndOfAbraxas'' comes from Sachiko asking Yumi to be her mistress after she marries her [[IncompatibleOrientation gay]] [[ArrangedMarriage arranged husband]]. Sachiko, being the {{ojou}} she is, words it as Yumi "living in the same room" (and, if Yumi likes, the same bed) as her, as "[[UnusualEuphemism an adopted family member]]".
* This is discussed in the first chapter of ''Fanfic/FakeVega62a'' due to the fact Sachiko is marrying a gay man. She guesses that Suguru will have his own lover, but wonders who will be her own. Sei is her first option for a mistress. Not because of the sex (Youko would be better for just that), but because she would kindly reject her advances.
* ''FanFic/TheNewRetcons'': It's revealed after [[spoiler: Elly's death]] that John had been cheating on her for two years, first with sex workers before making [[spoiler: Kortney]] this trope. She's also old enough to be his daughter and had previously stolen from Elly and threatened to beat up April.

* ''Film/FeastOfLove'': Diana is the long-term lover of David, a married man. They don't do anything except drink wine and have sex together, which she finds lacking, with her leaving him for Bradley. [[spoiler:After that, he also leaves his wife and they end up a happy couple as she leaves Bradley.]]

* In ''Film/InTheMouthOfMadness'', an InsuranceFraud scam is found out when a guy claims a warehouse full of [[PrettyInMink fur coats]] was supposedly destroyed, but he kept the coats, giving some to his wife, who ratted on him when it turned out he gave some to his mistress.

* ''Film/{{The Other Woman|2009}}'': Emilia plays the eponymous role. She has an affair with Jack, who's married. After becoming pregnant with their baby, Jack divorces his wife and [[RemarriedToTheMistress marries Emilia]].
* ''Film/{{The Princess|2022}}'': Moira is Julius' long-term lover, though he's going to marry the princess. She seems fine with that, and he likely can't marry her as she's a commoner.

* In ''Film/{{Revenge|2017}}'', Jen is the mistress to the wealthy Richard. Richard claims he is only staying with his wife because of the children. However, after Jen is raped by Richard's friend Stan, she threatens to tell his wife what is going on if he does not resolve the situation. Richard then demonstrates that he has no intention of leaving his wife, and decides that MurderIsTheBestSolution to get Jen out of the picture.

* ''Film/ShivaBaby'': Unbeknownst to her, Danielle's sugar daddy Max not only is married, but has a child, which shocks her, realizing that she's inadvertently been this for some time. [[spoiler:Later it comes out when his wife Kim is nearby.]]
* ''Film/SunshineCleaning'': Rose is in a long-term relationship with Mac, who's married to another woman. They even have a son together. She finally breaks up with him after realizing he's not going to leave his wife for her.

* In ''Film/WhatsTheWorstThatCouldHappen'', Max Fairbanks is two-timing his wife with a mistress and is an asshole to both of them. Strangely enough, he still is afraid of this affair being discovered (maybe because he doesn't want to lose any money in the divorce) so Tiffany (the aforementioned lover) manages to make Max do what she wants a couple of times during the film by threatening to tell his wife.

* The court in the ''Literature/{{Hurog}}'' duology has the official version - the queen's lover is appointed by the king, and the king has a male "favourite", who is country-wide known to be the one who shares his bed.
* In ''Literature/TheGreatGatsby'', this is BlueBlood Tom Buchanan's relationship with Myrtle Wilson, who herself has an unhappy marriage with an auto mechanic.
* In Katherine Kerr's ''Literature/{{Deverry}}'' series, Rhodry takes Jill as a mistress. He would have liked to marry her, and his allies do end up arranging things so she can be given a title to enable them to marry. However, fate has different plans in store for them and they can't... for reasons of destiny. It's acknowledged that this is common among the nobility due to the proliferation of political marriages; and in many cases the jilted spouse doesn't particularly mind as long as you are tactful and discreet.
* One interpretation of the poem "The Rival" by Creator/SylviaPlath (in ''Literature/ArielPlath'') is that the subject is an {{expy}} of the mistress of Plath's husband.
* ''Literature/{{Discworld}}'', ''Literature/MakingMoney'': The bank's previous owner was the former mistress and later wife of the former chairman, mentioning that as his mistress, she had the wife's approval because it got him out of her hair for a while. He also had other lovers after they were married, under the same kind of arrangement. She was also good with numbers, which is why she remained in charge of the bank after his death. Before she passed on, she noted that standards have dropped and that now "the ability to spin upside down on a pole is considered sufficient".

** {{Deconstructed}} in ''Literature/DuneMessiah'': Emperor Paul Atreides considers Chani, the woman who is technically his mistress, to be his true wife, and never consummates [[AltarDiplomacy his official (and political) marriage]] with Irulan Corrino, the daughter of the emperor he overthrew in the first book. This leads to court power games to everyone's detriment, [[spoiler:eventually resulting in Chani's DeathByChildbirth from complications of Irulan secretly dosing her with contraceptives, and Paul abandoning his crown to wander the desert until the next book]].
* Petra Cotes in ''Literature/OneHundredYearsOfSolitude'', doubling as one of the three [[HookerWithaHeartOfGold hookers with hearts of gold]].

** As part of the series's back story, King Aegon IV ("The Unworthy") had several semi-official mistresses, and thus several illegitimate children. As bastards, they weren't entitled to inherit, until the king legitimized them on his deathbed. Civil war resulted.
** Some high lords keep mistresses; but they have no official standing and the relationship is considered adulterous and immoral. Such mistresses are kept behind closed doors and the relationship is kept officially secret, even if it's common knowledge. (Tyrion Lannister's whore/mistress is treated in this way, lest she be used against him by Cersei, or killed by Tywin.)

* In ''Literature/LesMiserables'', Marius's grandfather has had many mistresses over the course of his life, and believes it's better to take a woman as a mistress than to actually marry her. When Marius tells his grandfather about Cosette, his immediate advice is to keep her as a mistress instead of as a legal wife (Marius, who reveres Cosette, finds the idea of dishonoring her so much to be unspeakable).
* In Creator/CharlotteBronte's ''Literature/JaneEyre'', Rochester's past is filled with lovers -- usually rich and well-known performers, such as Céline Varens. At the time of the novel, he says he's grown tired of keeping girlfriends. [[spoiler: After their would-be wedding is busted, Rochester offers this position to Jane. Jane realizes she could not possibly live with herself in this way, and leaves him.]]
* In ''Literature/InTheTimeOfTheButterflies'', [[UnnamedParent Papa]] has another family with three other children in addition to the four daughters he has with his wife.
* In ''The Literature/LastHeraldMageTrilogy'', King Randale's [[MindlinkMates beloved]] Herald Shavri is officially this, mainly because the option of a State Marriage had to be left open (partly because Shavri was terrified of being Queen). Their daughter Jisa is legally a bastard, though she marries back into the line of succession. This also starts a SecretLegacy in the Valdemar royal family, since [[ChosenConceptionPartner Vanyel is Jisa's actual father]].
* Goes both ways in ''Literature/StarCraftGhostNova''. It's explained that, due to marriages among the Confederacy's aristocracy on Tarsonis [[AltarDiplomacy being invariably political in nature]], it's expected that both husband and wife will have mistresses (called a "jig" in the wife's case, seemingly a shortened form of "gigolo"). Nova's parents hate each other so much they've apparently ''never'' actually had sex with each other: she was conceived via IVF.
* ''Literature/ElsabethSoesten'':
** Although he's not married, Lord Cuncz offers to make Elsabeth this at the end of ''No Good Deed...'' She rightly surmises he's really doing it as a means to keep an eye on her because S{{he Knows Too Much}} about his identity and declines. For his part, Cuncz remains gracious at her refusal.
** Cuncz himself [[spoiler: is the product of a relationship between a rival lord and his favorite mistress. The woman died in childbirth, and the local Abbot used the infant Cuncz as part of his efforts to build a power base against his ''own'' political rival]].
* ''Literature/TheCatInTheStacksMysteries'': In book 2, Hubert Morris is blatantly cheating on his mentally ill wife with his long-time lover, [[spoiler: Anita Milhaus. He even stole from his uncle James' rare book collection to finance the presents he bought for Anita, which is what draws Charlie into the situation when James hires him to inventory the collection and figure out what's missing]].
* ''Literature/AscendanceOfABookworm'': Taking mistresses is apparently a common practice among high-ranking men, to the point that young girls are sometimes promised as future mistresses as some sort of loose equivalent to an engagement. Noblemen, even the most low-ranking ones, are absolutely not supposed to properly marry outside of nobility, so the only NobilityMarriesMoney arrangement that is mentioned in the story has the "money" side slated to become a mistress. The male head of the temple doesn't have a wife, but plenty of mistresses. The children of mistresses are considered illegitimate children despite this, though having a noble father can let them get a few perks of nobility such as going to the setting's WizardingSchool.

* ''Literature/MaidenCrown'' has a slightly unusual example. Tove becomes this to King Valdemar after he marries Princess Sophie, but they were already lovers before he and Sophie were even betrothed. Valdemar only resumes their relationship when his marriage starts going through a rough patch.
* ''Literature/TheKeptManOfThePrincessKnight'': GenderInverted: Matthew is WarriorPrincess Arwin's "kept man", which amounts in practice to being her live-in housekeeper, manservant, and PTSD therapist, whom she pays an allowance out of dungeon loot. Their relationship is emotionally and physically affectionate, [[spoiler:but not actually sexual]].

* In the ''Series/{{Firefly}}'' episode "Shindig", Atherton Wing wanted Inara for one of these. Mal [[FumblingTheGauntlet objected]] to his possessivity, leading to a [[DuelToTheDeath sword duel over her honor]]. It's indicated in the pilot that Inara gets these kinds of offers on a regular basis, and [[spoiler:we find out after all's said and done that she had no intention of accepting the offer in the first place]].

** In a GenderInverted example, Loras Tyrell fulfills this role when his lover Renly Baratheon marries Loras' sister Margaery. Verges on an OpenSecret, if the amount of sarcastic references to the relationship is any indication. At one point, the exclusively homosexual Renly is trying to make excuses for not consummating the marriage, to which Margaery suggests in all seriousness that they bring Loras in to "get him started." Renly thinks this is an insult, but she actually fully accepts that the marriage [[TheBeard is a political sham while Loras is his real lover]]; she just thinks [[HeirClubForMen they need to have an heir to cement the alliance]].

-->'''Nadine:''' I swear, [[AssholeVictim I'm glad he's dead.]]

* On ''Series/MyNameIsEarl'', Earl had a BadBoss with a hot blonde wife and an equally hot brunette girlfriend on the side. When Earl punches him (landing him in the hospital), the two women show up to be by his side... and find out about each other's existence. When the (soon-to-be-ex) wife is giving him a DefenestrateAndBerate, she finds the money he's been laundering and he winds up in prison. He loses both his wife ''and'' his girlfriend... but he does become his cellmate's prison bitch. (With a coffee mug that has "World's Best Bottom" scrawled on it.)
* A GenderInverted version appears on ''Series/TheOfficeUS'', during the plotline where Michael thinks his girlfriend Donna is cheating on him, but it turns out that the "other man" is her husband: "''I'M'' the mistress?"
* In the first time in ''Series/QuantumLeap'' where Sam leapt into a woman, he was there to save "his" roommate from committing suicide over an relationship with her boss -- she thought her boss would leave his wife for her, but the wife made it clear to her that she tolerated his "indiscretions" but they would never break up (and she was a former mistress of the boss herself, having broken up his previous marriage).
* ''Series/{{Scandal}}'':
** Olivia Pope used to be the President's Press Secretary as well as his mistress. Mellie, the President's wife, knew about it and was generally fine with it since the marriage was purely a political one at this point. The people who knew assumed that when the President's term in office was over he would divorce Mellie and marry Olivia. However, Olivia threw a wrench into the arrangement by breaking off the relationship and quitting her job. Throughout the series the President tries to rekindle the relationship but Olivia is tired of the lies and betrayals. In season 2 the relationship between them turns outright toxic.
** One of Olivia's clients turns out to be a male example of this. He is in love with his brother's wife and they have been having a clandestine relationship for more than a decade. Olivia gives him a TheReasonYouSuckSpeech where she explains why such an arrangement is not a real relationship and he needs to end it if he wants to be ever truly happy. Of course she is partly talking about herself as well.
* ''Series/SexAndTheCity'': Carrie was effectively Mr. Big's mistress for a time, as they had sexual encounters behind his new wife's back. Carrie actually found the experience deeply humiliating, particularly when a [[{{Salaryman}} Japanese businessman]] who frequents the hotel where they meet for sex assumes she is a prostitute and tries to hire her.

* Hilariously, on the last season of ''Series/TheTudors'', Charles Brandon introduces his French girlfriend to people as his "official mistress". Less hilariously, in an earlier season, Henry offered this position to Anne Boleyn when he was still married to Catherine of Aragon. To say that Anne refused is underselling the reaction.

* "Can't Let U Go" by Fabolous is about a man who is already married, and is torn between his wife and his girlfriend (and trying to keep the former from finding out about the latter). For now, he decides to secretly have his cake and eat it too, because "the entree ain't as good without something on the side". For her part, the mistress knows full well that her boyfriend is already married, and is apparently OK with the status quo.
* "Two Weeks" by Music/FKATwigs is sang in the perspective of an aspiring one, saying that all she needs is, in fact, two weeks to make her target of affection forget about their loved one.
* "Saving All My Love For You", by Music/WhitneyHouston, is from the mistress's [=POV=] as she laments that her paramour is being about as honest with her as he is with his wife and family.
* "Two Black Cadillacs" is a MurderBallad by Music/CarrieUnderwood about two women who find out that their husband and boyfriend, respectively, has been two-timing them, and collaborate to kill him. They get away with it, too.

** {{Defied}} by the narrator of "[[Music/Red2012 Girl at Home]]," who is pursued by a man who has a girlfriend. She rejects him out of hand, and gives him a TheReasonYouSuckSpeech, explaining that she's been cheated on in the past, would never put another woman through that, and feels a responsibility to set him straight. She basically tells him he's an immature loser, and to get his act together and appreciate the woman he has.

[[folder:Pro Wrestling]]
* Wrestling/VinceMcMahon Jr has had several, the most famous of them being Wrestling/TrishStratus. Stratus did very little to hide her status, thinking herself hot stuff, and part of what made her role famous was a rare feud that had Jr's daughter Wrestling/StephanieMcMahon as a baby {{face}} of [[ALighterShadeOfGrey sorts]] against Trish. The other famous part was when Vince Jr made it publicly known that Trish was just a toy he was getting bored of, and had her on all fours barking like a dog to keep her job. This had the side effect of [[HeelFaceTurn turning Stratus face]] against the entire [=McMahon=] family, [[FaceHeelDoubleTurn Stephanie included]], ''except'' Vince Jr's wife Linda, who was oddly sympathetic towards Trish in spite of her displeasure with her husband's infidelity.
* Wrestling/TorrieWilson, [[Wrestling/LisaMarieVaron Victoria]] and Wrestling/CandiceMichelle, the GirlPosse known as Vince's Devils, had the distinction of serving as Vince Jr's mistresses all at once while feuding with a former mistress of Jr's, Trish Stratus. Granted, the feud was over Wrestling/AshleyMassaro asking Stratus for help after weeks being bullied by the three, as well as Stratus having the women's title belt that said Devils ended up [[BackStabbingTheAlphaBitch turning on each other over]]. Still, there was a moment when Michelle had the [[{{hypocrite}} gall]] to call Stratus a {{slut|shaming}}.
* Ultimately turning company employees into his mistresses in exchange for benefits proved to be Main/TruthInTelevision for [=McMahon=] and the reason for [[Main/LaserGuidedKarma his downfall]].

* ''Theatre/CyranoDeBergerac'': [[{{Villains}} De Guiche]] wants to bully heroine Roxane into this. She will have none of it.

* The ''VideoGame/PrincessMaker'' series:
** ''VideoGame/PrincessMaker2'':
*** There's a possible ending with the girl as the lover of a local landlord as well. Said landlord [[ChekhovsGunman can potentially show up earlier]] and make the girl his lover if she has high Charisma with low Morals -- it's not recommended to just let her be, though, as she'll get a rather nice allowance from him every month but her stats and overall rep will go lower.
*** The King of the Land also has a royal concubine, and the daughter can speak to her. She seems to be a pretty but deadly bored woman rather disenchanted with the life of the court, but unwilling to leave it due to the benefits it still gives her.

** In ''VideoGame/FireEmblemTheBlazingBlade'' King Desmond of Bern has a son (Zephiel) by the queen (Helenne), and a daughter (Guinevere) by his [[NoNameGiven unnamed]] mistress. His illegitimate family lives in the palace, while his official one lives in an old out-of-the way manor. It's explained in the earlier-released ''VideoGame/FireEmblemTheBindingBlade'' that [[spoiler:said mistress was actually the King's old girlfriend, whom the King couldn't marry due to being forced in an ArrangedMarriage with the Queen..]] Needless to say, [[BigScrewedUpFamily it does NOT end well.]]
** In ''VideoGame/FireEmblemFates'', King Garon of Nohr had ''many'' mistresses and some of these women gave him children. This made the DecadentCourt ''even worse'' than it already was, as the concubines started in-fighting each other and using their kids as leverage; it got so bad that out of all the kids born and raised in such an entourage, only four remained (one of them being the sole legitimate child and heir).
*** It's quite strongly implied that [[spoiler: Mikoto, the widow of King Sumeragi and the Queen Regnant of Hoshido, was his mistress first [[RemarriedtoTheMistress and only married him after he was widowed]]. Unlike the above-mentioned Garon's case, Mikoto was Sumeragi's ''only'' known lover (especially in the localization, which takes away a line implying that Sumeragi used to sleep around before being enthroned) and that she never gave him children - the mother of the Hoshidan Royal Siblings was the late legitimate Queen, Ikona, whereas Mikoto's child (the Avatar) was already born ''before'' she arrived to Hoshido, and [[ArchnemesisDad his/her birth father is someone else]].]]
* In ''VideoGame/DragonAgeOrigins'', [[spoiler:if a Female Warden makes Alistair king and cannot/will not make herself queen and are in a romance, and provided he became "hardened" earlier, she may become his mistress. Not just a mistress, though, she may be his adviser, as well. A human noble Warden who marries the new monarch but is in a relationship with Zevran or a hardened Leliana can similarly keep their lover around.]]
* Further on down the series line, ''[[VideoGame/DragonAgeInquisition Inquisition]]'' companion Vivienne has a lot of political clout for a mage due to being the mistress of an Orlesian count. His wife approved of the situation; the two of them got along splendidly, and Vivienne still mourns her death.
* In ''VideoGame/TalesOfSymphonia'', Zelos' father had a half-elf mistress, who was the mother of Zelos' half-sister Seles. Despite him being the Chosen, it's implied that it was something everyone knew, as Zelos and Seles not only knew about each other, but they got on rather well. The mistress wasn't happy with the arrangement though, knowing that Zelos would be TheChosenOne instead of her daughter... [[spoiler: so she tried to murder Zelos with a powerful spell. She got to kill Zelos' mother instead, who died saying she wishes he'd never be born. The mistress was executed for treason, an emotionally broken Seles was sent away, and Zelos [[BrokenAce was thoroughly shattered]].]]
* In ''VideoGame/PretentiousGame 3'', the bright pink square is the gray square's mistress while he's married to the light pink square.
* ''VideoGame/MassEffectAndromeda:'' If romanced, Keri T'Vessa assumes she's one for Ryder, while Ryder's off exploring the Heleus Cluster.

* In ''VisualNovel/UminekoWhenTheyCry'', several characters theorize early on that the basis of the legends of Beatrice, the mysterious witch that Kinzo Ushiromiya seems to be obsessed with, is that Kinzo had a secret mistress (though Natsuhi, trying to be the loyal daughter-in-law, repeatedly tries to deny it). It turns out that [[spoiler:they're right. Kinzo did have a mistress, an Italian beauty named Beatrice Castiglioni, who he met during the second World War. They fell deeply in love, and after Kinzo bought the island of Rokkenjima he built her a secret mansion, Kuwadorian, for her to live in, and he would often visit her under the pretense that he was going on business trips. They even had a daughter, but unfortunately Beatrice [[DeathByChildbirth died in childbirth]]...and this caused Kinzo to go insane with grief, and as their daughter grew older he convinced himself that she was his mistress reincarnated, [[ParentalIncest eventually leading him to rape her and get her pregnant]] with the kid who'd grow up into Sayo "Yasu" Yasuda, one of the key characters of the game.]]

* ''Webcomic/MenageA3'': Plays with the trope to comedy effect when it turns out that ''both'' Amber and Dillon are playing the mistress to sleazy {{Transparent Closet}}ed bisexual producer Nathan.

[[folder:Web Original]]
* ''WebVideo/SabatonHistory'': {{Parodied}} in the producer segment for [[https://www.youtube.com/watch?v=PX9y7z1qndQ "The Last Battle"]] when Joakim facetiously refers to "Jenny" from the song as "my longtime lover". (The line actually refers to ''Besotten Jenny'', the M4 Sherman tank that [[https://en.wikipedia.org/wiki/Battle_of_Castle_Itter Captain Lee brought with him to Castle Itter]].)

'''Joakim:''' I hope not! ''(cut to TV color bar screen with a tank in a heart pasted over it)''

* Nurse Bendy, to Principal Fakey on ''WesternAnimation/MoralOrel''. She's pretty nonchalant about it. [[spoiler: Though the episode Alone, implies that her mental state has regressed to that of a child, and that sleeping around has made her affection starved and depressed.]]
* There's a GenderInverted example on ''WesternAnimation/KingOfTheHill''. There is an OpenSecret that Nancy has been having a 14 year affair with John Redcorn. Her husband Dale and son Joseph (who happens to look exactly like John, a brown-skinned Native American) are completely oblivious.

* [[https://en.wikipedia.org/wiki/Madame_de_Pompadour Madame de Pompadour]], was one of the [[https://www.wga.hu/html/b/boucher/2/pompado1.html mistresses]] of [[UsefulNotes/LEtatCestMoi Louis XV]]. She was featured in ''Anime/LeChevalierDEon''. She also appeared in the ''Series/DoctorWho'' episode [[Recap/DoctorWhoS28E4TheGirlInTheFireplace "The Girl in the Fireplace"]] (the Doctor even mentions that she and the queen were good friends).

** The position is {{deconstructed}}, as Paul Atreides [[Literature/DuneMessiah considers Chani, the woman who is technically his mistress, as his true wife, and never consummates his official (and political) marriage]] with his actual wife, the daughter of the emperor he overthrew in the first book.
** Going back a generation, Paul's mother [[Literature/{{Dune}} Jessica is the 'bound concubine' of Leto Atreides]], and presumably if he'd married she would have been this -- but the two of them consider themselves married in everything but name.

* Goes both ways in ''Literature/StarCraftGhostNova''. It's explained that, due to marriages among the Confederacy's aristocracy on Tarsonis [[AltarDiplomacy being invariably political in nature]], it's expected that both husband and wife will have mistresses (called a "jig" in the wife's case). Nova's parents hate each other so much they've apparently ''never'' actually had sex with each other: she was conceived via IVF.

* Practically ''all'' the Bourbon kings of Spain have had their fair share of infidelities: For instance, King Alfonso XII was a well-known bohemian and had several paramours, while his son Alfonso XIII reportedly spent time with his mistresses in the presence of his wife, which did nothing to help the monarchy's reputation. And later on, King Emeritus Juan Carlos was often featured on gossip magazines in the company of younger women until a major scandal erupted after it transpired that he was practically living a second life with his latest mistress, which led to rumours about this being a factor on his abdication some time before. Curiously, his son, the current King Felipe VI has been the butt of some jokes about his ''not'' having had any allegations of infidelities as of yet.

* Wrestling/TorrieWilson, [[Wrestling/LisaMarieVaron Victoria]] and Wrestling/CandiceMichelle, the GirlPosse known as Vince's Devils, had the distinction of serving as Vince Jr's mistresses all at once while feuding with a former mistress of Jr's, Trish Stratus. Granted, the feud was over Wrestling/AshleyMassaro asking Stratus for help after weeks being bullied by the three, as well as Stratus having the women's title belt that said Devils ended up [[BackStabbingTheAlphaBitch turning on each other over]]. Still, there was a moment when Michelle had the [[{{hypocrite}} gall]] to call Stratus a {{slut|shaming}}.[[/folder]]

[[folder:Radio]]
* In ''Radio/TheMenFromTheMinistry'' Ms. Bentwater of the typing pool is this to [[DirtyOldMan Sir]] [[BadBoss Gregory]].

* ''[[Anime/{{Patlabor}} Patlabor: The Movie 2]]'': Back when [[spoiler: Shinobu]] was a cadet at the Tsuge Institute, she had an affair with the instructor, himself, despite knowing he was married. It was both a breach of police protocol and ethics. Word of the affair soon got out, reaching as far as he top brass, which created a scandal[[note]]though it isn't said whether Tsuge's wife ever found out he was cheating on her with one of his students[[/note]]. The stigma barred [[spoiler: Shinobu from ever attaining a seat among the higher-ups, which forced her to settle for a position at the SVU]][[note]]Shinobu would have likely gained a position on the Tokyo Metropolitan Police Management Bureau, had it not been for the affair[[/note]].

** In a GenderInverted example, Loras Tyrell fulfills this role when his lover Renly Baratheon marries Loras' sister Margaery. Verges on an OpenSecret, if the amount of sarcastic references to the relationship is any indication. At one point, the exclusively homosexual Renly is trying to make excuses for not consummating the marriage, to which Margaery suggests in all seriousness that they bring Loras in to "get him started." Renly thinks this is an insult, but she actually fully accepts that the marriage [[TheBeard is a political sham]] while Loras is his real lover; she just thinks [[HeirClubForMen they need to have an heir to cement the alliance]].

* ''Series/FellowTravelers'': [[PlayingWithATrope Played with]] in Hawkins Fuller and Tim Laughlin's relationship. Immediately after Hawk tells Tim that he plans to ask Lucy Smith to marry him, Tim enlists in the army because he is determined to ''not'' become [[GenderInvertedTrope the male equivalent]] of a mistress for Hawk. However, in spite of his attempts to cut ties with Hawk and move on with his life, Tim remains in love with Hawk, and falls into bed with him every time they see each other in the ensuing decades. On more than one occasion, [[LampshadeHanging Tim laments his own inability to say no to Hawk]].

* ''Series/InterviewWithTheVampire2022'': For most of Season 1, Antoinette Brown is this for Lestat de Lioncourt, who is in a [[MetaphoricalMarriage committed relationship]] with Louis de Pointe du Lac. Whenever Lestat feels that Louis isn't paying enough attention to him sexually, he "entertains" and "amuses" himself with Antoinette instead.

* ''Series/FellowTravelers'':[[PlayingWithATrope Played with]] in Hawkins Fuller and Tim Laughlin's relationship. Immediately after Hawk tells Tim that he plans to ask Lucy Smith to marry him, Tim enlists in the army because he is determined to ''not'' become [[GenderInvertedTrope the male equivalent]] of a mistress for Hawk. However, in spite of his attempts to cut ties with Hawk and move on with his life, Tim remains in love with Hawk, and falls into bed with him every time they see each other in the ensuing decades. On more than one occasion, [[LampshadeHanging Tim laments his own inability to say no to Hawk]].

* ''Series/DoctorWho'': [[Recap/DoctorWhoS28E4TheGirlInTheFireplace "The Girl in the Fireplace"]] revolves around Madame de Pompadour, the mistress of King Louis XV Bourbon of France.

** Melisandre for Stannis, though they only have sex once to spawn the LivingShadow that kills Renly.

* ''Series/TheMusketeers'': In the second season King Louis XIII takes Milady de Winter as his official mistress leaving Queen Anne humiliated by his publicly flaunting Milady. Aramis, who has feelings for Anne, is furious at the way she's being treated and Athos, who used to be ''married'' to Milady, is so unable to deal with it that he abandons guard duty and returns to the garrison so he can avoid them.

* An extremely rare GenderFlip version appears on ''Series/TheOfficeUS'', during the plotline where Michael thinks his girlfriend Donna is cheating on him but it turns out that the "other man" is her husband: "''I'M'' the mistress?"
* In the first time in ''Series/QuantumLeap'' where Sam leapt into a woman, he was there to save "his" roommate from committing suicide over an relationship with her boss - she thought her boss would leave his wife for her, but the wife made it clear to her that she tolerated his "indiscretions" but they would never break up (and she was a former mistress of the boss herself, having broken up his previous marriage).

* ''Series/TheWestWing'': Towards the end of the second season Sam Seaborn learns that his father has been having a long-term affair with another woman. While he initially tries to act dismissive it's clear that he's deeply hurt by the betrayal by someone he respected.

* There's a GenderFlip on ''WesternAnimation/KingOfTheHill''. There is an OpenSecret that Nancy has been having a 14 year affair with John Redcorn. Her husband Dale and son Joseph (who happens to look exactly like John, a brown-skinned Native American) are completely oblivious.

** In a rare male example, Loras Tyrell fulfills this role when his lover Renly Baratheon marries Loras' sister Margaery. Verges on an OpenSecret, if the amount of sarcastic references to the relationship is any indication. At one point, the exclusively homosexual Renly is trying to make excuses for not consummating the marriage, to which Margaery suggests in all seriousness that they bring Loras in to "get him started." Renly thinks this is an insult, but she actually fully accepts that the marriage [[TheBeard is a political sham]] while Loras is his real lover; she just thinks [[HeirClubForMen they need to have an heir to cement the alliance]].

* A lot of the drama in ''Fanfic/{{Metamorphosis}}'' comes from Sachiko asking Yumi to be her mistress after she marries her [[IncompatibleOrientation gay]] [[ArrangedMarriage arranged husband]]. Sachiko, being the {{ojou}} she is, words it as Yumi "living in the same room" (and, if Yumi likes, the same bed) as her, as "[[UnusualEuphemism an adopted family member]]".

* ''Franchise/WonderWoman'' [[ComicBook/WonderWoman1942 Vol 1]]: Lisa Abernathy has been in a long term secret relationship with the married senator Brad Covington, who is implied to be her elementary school aged daughter's father. She is pissed when she realizes Gen. Darnell has figured out that she and Brad are dating.

* Helen's husband Charles has one in ''Film/DiaryOfAMadBlackWoman'' , and she even had two children with him (meanwhile Helen had two miscarriages).

* ''Film/FeastOfLove'': Diana is the long-term lover of David, a married man. They don't do anything except drink wine and have sex together, which she finds lacking, with her leaving him for Bradley. [[spoiler:After that he also leaves his wife and they end up a happy couple as she leaves Bradley.]]

* ''Film/KapoorAndSons'': Harsh and Sunita's marriage is on the rocks in part because he had an extramarital affair with a woman named Anu, which has not yet ended.

* In ''Film/{{Revenge|2017}}'', Jen is the mistress to the wealthy Richard. Richard claims he is only staying with his wife because of the children. However, after Jen is raped by Richard's friend Stan, Jen threatens to tell his wife what is going on if he does not resolve the situation. Richard then demonstrates that he has no intention of leaving his wife, and decides that MurderIsTheBestSolution to get Jen out of the picture.

* In ''Film/WhatsTheWorstThatCouldHappen'', Max Fairbanks is two-timing his wife with a mistress and is an asshole to both of them. Strangely enough he still is afraid of this affair being discovered (maybe because he doesn't wants to lose any money in the divorce) so Tiffany (the aforementioned lover) manages to make Max do what she wants a couple of times during the film by threatening to tell Max's wife.

* ''Series/TheWhiteQueen'': Jane Shore is King Edward IV's favourite mistress.

** [[UsefulNotes/TheHouseOfPlantagenet Edward IV]] seems to have slept with something like half the married noblewomen in England. Interestingly, this seems to have helped him politically, as his mistresses would influence their husbands to support him in the War of the Roses.

** Laenor Velaryon is betrothed to Rhaenyra Targaryen, but [[TheBeard he is not interested in heror indeed any other woman]], and instead keeps a male paramour named Joffrey Lonmouth, who seems to be happy with the arrangement. However, when Rhaenyra offers the same status to Ser Criston Cole ([[RetargetedLust whom she had impulsively banged after her rejection by Daemon]]), the latter does ''not'' take this well, knowing that he will be gelded if his sworn brothers learn that he has broken his oath to the Kingsguard. Things go worse when Joffrey attempts to befriend Criston as "fellow paramours" during Rhaenyra's and Laenor's wedding, as Criston, angry and fearful of his fate, ends up beating Joffrey to death.

* ''Series/HouseOfTheDragon'': Daemon Targaryen is legally married to Rhea Royce, but their relationship is estranged, to say the least (he once called her the "bronze bitch"). Instead, he has an affair with a foreign dancer named Mysaria, who provides genuine emotional support to him. [[spoiler:By the fourth episode, however, Mysaria seems to have fallen out of favor with Daemon following the latter's years-long campaign in the Stepstones, and is building a spy network in King's Landing.]]