A sister trope to Luke, I Am Your Father, this is when the revelation exists not that a person in question is a character's father, but he might be. It turns out that they had sex with the character's mother at about the same time as the fertilization, so the possibility exists. The thing is, they probably aren't the only person who did so.
A common result of the invocation of this trope is that someone uses either science or magic to determine who the real father is. How long this takes depends on the speed of the plot.
As it is predicated on Mama's Baby, Papa's Maybe it is an Always Male trope in most cases. Female cases are still possible, when the mother is separated from her child shortly after birth. See also Ambiguously Related.
Note that DNA testing good enough to establish the truth is relatively recent; in historical settings, possible father and possible child will often be left hanging and have to do their best to work things out without knowing.
Obviously, spoilers are involved here.
- Ino-Head Gargoyle: Saejima runs into a former girlfriend, who has a kid whose age matches when they broke up. He even looks like Saejima. She confirms it's his son.
- Marube notes this to his daughter in Yuureitou, noting that it's impossible to know for sure (but it is unlikely) that they're biologically related. After years of Parental Incest this is the last strike that leads to Satoko running away.
- In Sonic X, it's heavily hinted (but never outright stated) that Dark Oak is Cosmos's father due to the fact she's the last child of Earthia, who was Dark Oak/Lucas' wife.
- Used in Northwest Passage. Montglave informs Simon at the climax that he raped his mother at about the time he was concieved. He does this in an attempt to completely turn Simon against Charles Lord, the other possible candidate. Unfortunately for him, being a sociopath, he failed to consider that Simon would react less than positively to the news that Montglave had raped his mother.
- In Avengers Academy, Finesse and Taskmaster think they might be related because of their similar special abilities. Taskmaster doesn't deny the possibility but states that he's been with quite a few women and he couldn't possibly narrow down Finesse's mother even if he didn't have memory problems. He also refuses to take a Daddy DNA Test because he doesn't want the government to get a sample of his DNA. Taskmaster still spars with Finesse once to memorize her movements, since it's the only surefire way he will remember her.
- Barbara Gordon once discovered that Jim Gordon might have been sleeping with his brother's wife (Barbara's mother) at the time Barbara was conceived. She decided not to pursue the matter any further. Later this was retconned to have Jim always be her dad and actually be married to her mother.
- It's been strongly suggested that Carmilla Black, aka Scorpion (unrelated to the Spider-Man villain), is the biological daughter of Bruce Banner, due to his college fling with her mother, Monica Rappaccini, Scientist Supreme of A.I.M.
- Wonder Woman (1987): During The Contest Diana gets a bunch of visions implying Hercules is her father, and Hippolyta repeatedly makes it clear her word can't be trusted and that she's mislead Diana about her past so when Diana confronts her mother and Hippolyta insists she was born of clay and that Herc isn't her father her words are undermined by her own actions and the situation is left ambiguous, though the obvious editorial intent was that the clay origin should be considered the most likely.
- Officer Fred Chyre, a Friend on the Force for The Flash, told Wally West that Chyre's dead partner Julie Jackam was only survived by her infant son, and Chyre believes that Wally is the father, since Wally and Julie previously dated, and the baby is exhibiting superpowers. Shortly after this however, the Weather Wizard shows up because he used to be Julie's boyfriend like Wally was, and reveals that he is the actual father.
- Ultimate X-Men: Wolverine met Magda and had sex with her, which angered her husband, Magneto. He simply threw him out of the window, down a mountain. Many years later Wolverine joined the Brotherhood, with Magneto ignoring that Wolverine was Magda's lover (since by this point Magneto was determined to ignore the fact he'd ever been in a relationship with a filthy non-mutant). Wolverine was shocked to see Quicksilver and the Scarlet Witch (especially the latter, as she looked so similar to her mother and even used a similar costume), and wondered if they may be his children. As of Ultimate Wolverine, it turns out that they did have a child, but it's not the twins, it was Jimmy Hudson.
- In Bad Future Crusaders, it is very strongly implied that Crimson Sky, The Dragon of the R.E.A.F, is Scootaloo's father. He is completely unaware while Scootaloo is aware of the possibility after hearing him quote her mother and claim it was "something his ex used to say".
- After Vanessa Foster reveals she's Pete's biological mother in Star Spangled Spider, she states there are three possible men that could be his father: Tony Stark, Steve Rogers, and Bucky Barnes. Later on, as both Nick Fury and a paternity test reveal, Peter's father is Steve.
- The Victors Project: Ben Cooper's "secret" is that he suspects his mentee and fellow Victor Abram Mills might be his biological son from a one night stand he had with Abram's mother Caramel. It's actually why he came out of retirement to mentor Abram in the first place. Whether it's true or not, Abram certainly took after Ben in the end when he rallied District 9 during the revolution and led them against the Capitol forces, ultimately dying after taking down a literal mountain of peacekeepers with him.
- In Rob Roy MacGregor's wife is raped by Cunningham, who keeps it a secret from her husband knowing that it was intended as an attack against him. When she is subsequently pregnant, Cunningham's associate Killearn threatens to tell MacGregor not only about the rape, but that Cunningham may well be the father of the unborn child. She doesn't take this threat well. Even though this threat turns out to be a bit pointless, because she tells him anyway and he refuses to hold it against her or the child. Cunningham is another matter.
- Men in Black II. It's heavily implied K is Laura/The Light of Zartha's birth-father.
- Mamma Mia! is a mix of this and Luke, You Are My Father, as Sophie's telling her three maybe-dads that they're her father(s). Judging by their appearance, it's probably Bill.
- The basis of the 1983 French film Les Compères: Gerard Depardeau and Pierre Richard argue over which of them is a young man's biological father. At the end, he tells them both that they're the real one and asks them not to tell the other to spare their feelings.
- Star Wars: Ironically, the Trope Namer for Luke, I Am Your Father himself suffers this. In The Phantom Menace, Shmi Skywalker insists that there was no biological father she knows of, with Word of God later stating that Anakin was directly conceived by the Force. In Revenge of the Sith, Chancellor Palpatine talks to Anakin about a Sith Lord named Darth Plagueis who could use the Force to create life, and then later implies that same Plagueis was his own Sith mentor, suggesting—assuming that Villains Never Lie, which is far from guaranteed with Darth Sidious—that Plagueis might have been Anakin's "father". This was sort-of confirmed in the Star Wars Legends novel Darth Plagueis: according to that book, the Force created Anakin as a reaction to Plagueis tampering with it in his experiments. However, the Disney-era Star Wars Expanded Universe novel Queen's Peril stated that Sidious was the sole Dark Lord of the Sith in the film period, and left it an open question whether Plagueis ever even existed in the new canon.
- Bullet to Beijing. Nikolai's father was a British spy seduced by a Honey Trap. Harry Palmer denies being that man. Nikolai thinks he's lying, and chooses to save his life.
- In The Revengers, Chamaco is obsessed with the idea that Benedict might be his father. Benedict, for his part, denies this. The movie ends and Chamaco dies without the issue being resolved one way or the other.
- The Life Aquatic with Steve Zissou, protagonist Steve Zissou (played by Bill Murray) meets Ned Plimpton (played by Owen Wilson) who says he is Zissou's son. Shortly after, Zissou hilariously introduces Plimpton saying, "This is Ned. He's my son, probably." Turns out he's not as it is later revealed that Zissou is sterile, but by that point in the story, he and Ned have become as close as father and son.
- Joker (2019), Penny Fleck (Joker's mother) claims that Thomas Wayne (Batman's father) is Joker's father.
- Inheritance Cycle: Murtagh, son of Morzan, discovers that he and Eragon share a mother, and assumes that they are both sons of Morzan. Actually, Eragon's father is Brom.
- The Alan Dean Foster Humanx Commonwealth novel The End of the Matter. Skua September tells Flinx that he might be Flinx's father because he donated genetic material to the Meliorare Society, which created Flinx using genetic engineering.
- In Stormrider, Gaise Macon is puzzled at the strained relationship with his father. The Moidart keeps him at arm's length and shows no clear sense of fatherly affection. And yet he still requires pain treatments for the horrible burns he suffered when he rushed into the burning mansion to save Macon as a child. Macon eventually learns that this is becauseconceivedime he was conceived the Moidart's wife was involved in an affair with a Highlander who was one of the Moidart's chief enemies. Macon would appear to be his son, because they both have a distinctive golden eye, but the Moidart's grandmother also had such an eye so he could never be certain of the truth. When Macon enters into A God Am I status near the end of the book, he finds out who his true father is—and tells the Moidart it was him. However, it is left ambiguous as to whether or not he was telling the truth.
- In the Outlander series, Brianna loses her virginity to Roger, and then gets raped the next day. It takes awhile to figure out who her baby's daddy is.
- Dezi in Darkover 's mother boinked about six different guys while wasted one night, none of whom will claim him as his own (well, one of them was going to claim him as a son, but didn't live long enough to do it). Dezi is really, really pissed about that.
- Krasta in Harry Turtledove's Darkness Series books was banging an Algarvian (German) officer, but slept with a Jelgavan (French?) nobleman on the side, so that when the Algarvians were forced out of Jelgava she could claim the Jelgavan noble was the father while still enjoying the privileges of being an Algarvian's bedwarmer. If the child exhibits Algarvian features when it is finally born, though, she is in quite a mess. It did, and she was.
- Maximum Ride: The Director of Itex claims that she is Max's mother. Turns out that the Director is only the one who designed Max, and that Dr. Martinez is Max's actual mother. Jeb Batchelder, The Mole, turns out to be Max's father.
- In Zadie Smith's White Teeth, Irie has to accept she may never know which man is her baby's father: the two possible candidates are identical twins, so DNA testing wouldn't help.
- Mentioned in the Belisarius Series as a potential threat to the stable future of Auxum. To avert it, after Eon dies, Ousanas makes a point of being away from the kingdom (and his new wife) for at least a year to ensure that there's no way any of his descendants can make a claim on the throne by arguing that they were plausibly conceived by the dead king: there'd simply be too much time between his death and the birth of the next child.
- The Unicorn Chronicles: In The Song of the Wanderer, Cara meets the Queen's Players, a group of human performers traveling around Luster. The group includes the acrobat Jacques, who was once married to Cara's grandmother Ivy Morris. He is uncertain if Cara's mother Martha was his child, or the child of someone Ivy met on Earth; either way, as far as he's concerned, any grandchild of Ivy's is his as well.
- A version shows up in The Trials of Apollo, though it's a bit unusual in although it's the identity of the father that gets questioned, there's absolutely no clue as to the second father or biological mother's identity. Instead a character claims a child as his younger sibling and refuses to explain what he means- his mother died long before the child would have been conceived, but his father has no memory of fathering the child.
- RCN: Part of the plot of The Way to Glory involves Daniel Leary's estranged father Corder Leary believing that a midshipman whom Daniel's new CO, Commander Slidell, spaced for mutiny on his last voyage was Corder's bastard son from an affair, and demanding that Daniel avenge him (which Daniel is wholly against doing: he's a soldier, not a murderer). Post-climax, Adele Mundy digs through RCN records offscreen and is able to prove genetically that the midshipman was not a Leary by-blow, but in fact the son of Slidell's brother, whom Corder's mistress was also sleeping with.
- An episode of Dharma & Greg featured Dharma becoming convinced that Greg was the father of his ex's son. It's all a big misunderstanding.
- In another episode Dharma's old friend shows up and starts spending a lot of time with Dharma's father, Larry. She eventually reveals that she thinks Larry might be her father, and she wants to spend some time with each of the possible candidates just so she's sure she got to know her dad at some point in her life. Larry turns out to be her favorite, and Dharma chooses not to reveal proof she found that Larry is not the real father.
- One episode of Boston Legal dealt with the squick ensuing when Denny Crane meets a girlfriend's mother and realizes to his horror that he used to have a sexual relationship with her-at about the time his girlfriend would have been conceived. It's not him.
- On House, it's established that House's mother often cheated on his father. House is aware of this, and wonders if the man who raised him is really his biological father. When his father dies, House manages to secretly cut off a little bit of the corpse's hair to do a DNA test. It turns out the dead man isn't House's biological father, and so House develops a theory that a Unitarian minister that is a long-time friend of his parents might actually be his dad. He gets especially suspicious of this when his mother starts an open relationship with the minister after his legal father's death. He manages to sneak a napkin that the minister used out of the restaurant after having dinner with the man and his mother, and does a DNA test on that, but it turns out negative. It is never established after that who House's biological father is.
- Luke from Gilmore Girls is revealed to have a possible daughter in season 6, she does a DNA test for a science fair to find out which of three men is her father. Luke ends up being the right one.
- My Two Dads: One of the two is the girl's father, but we never find out who, and the guys eventually acknowledge they don't really want to know.
- Used in Star Trek: The Next Generation as part of a plot by the Ferengi to blackmail Picard, although the idea came from somebody who was out for revenge from a previous episode. Nitpickers wonder about how much effort was required. Find a kid who Captain Picard might have fathered, the true identity of the father must be unknown, the mother must be out of the picture to prevent blabbing, and so forth. After all, for Kirk? Easiest mission ever. Picard, on the other hand, is a little too much of a responsible adult for it to be completely plausible. That the whole thing was motivated by Revenge Before Reason on the part of someone with a vendetta against Jean-Luc makes it slightly more plausible, however. And for the record, he wasn't the father.
- Alias: Sidney and Sloane.
- An episode of Moonlight had the vamp main character (back when he was human) getting involved with his war-buddy's (presumed) widow. The buddy then turned up alive, but the resulting kid was presumed to be very premature. He was.
- Two and a Half Men:
- Alan believes he is the father of his ex-wife's daughter, not her new husband, Herb. This is Left Hanging (aside from a dream sequence).
- Not quite related to potential parental lineage, but a Christmas episode had Charlie preparing to sleep with a blonde he met at a Christmas party (mostly just to spite his mother, who was strongly suggesting against it). It later turns out the blonde was potentially Charlie's half-sister by Charlie's late father (Charlie's parents had a "wife swap" with their neighbours, which apparently resulted in the husband "losing interest in conventional sex"). This ended up having Charlie's bar on who to sleep with raised somewhat.
- Yet another episode had an old girlfriend of Charlie's — with whom he broke off around eight years ago — showing up in town with a little boy in tow who looks suspiciously like Charlie. She calls him Chuck, dresses him in Charlie's signature style, and casually mentions that he plays the piano (as Charlie does.) Charlie spends the episode wrestling with the idea that his irresponsibility might actually have serious repercussions this time, and finding it within himself to step up and offer to be in the boy's life, then paying her child support when she rebukes his offer. Turns out the kid isn't even hers; she's babysitting him and his name is Ryan.
- Veronica Mars: In the first season, Veronica has reason to suspect Jake Kane-the father of her ex-boyfriend Duncan, and former lover of her mother-might be her biological father. He isn't.
- The Supernatural episode "The Kids are Alright" has Dean meet up with a woman he slept with once and find out that she's now a single mother. Her son is about the right age to be Dean's and even acts a little like him, has similar tastes, etc. It turns out he's not the father, though-she explains the similarities as her having a type, i.e. the actual father was like Dean because that was the kind of guy she went for.
- This was later given an "Or Is He" when said woman and her son were brought back as recurring characters in the sixth season. A demon possessing her taunts Dean with the knowledge that he might actually have been the father and Lisa had lied (or been mistaken) about it for whatever reason, but the demon is exorcised and Lisa's memory wiped before Dean can find out for certain either way.
- Every other episode of Maury is themed "I slept with
two sevensixty-three men; who's my baby's daddy?" In fact, "You are / are not the father!" is practically his Catchphrase.
- Ditto Jerry Springer (and most other daytime television of that ilk, for that matter).
- My Name Is Earl was cancelled on an episode with a plotline in which Earl and friends try to determine the parents of two kids. They determine that Earl is Dodge's dad, but Earl Jr. was Left Hanging.
- On It's Always Sunny in Philadelphia Frank may or may not be Charlie's real father in addition to being Dee and Dennis' adoptive father. Charlie's mom, it turns out, got around quite a lot.
- Shirley became pregnant in season 2 of Community, and was uncertain whether the father was her ex-husband Andre (they had recently reconciled) or Senor Chang (they had gotten drunk and had sex at a Halloween party). When the baby was delivered at the end of the season, they deduced that the father was Andre.
- In another episode, Professors Hickey and Duncan are having a drink and talking. It turns out that Hickey had spent quite a lot of time in the English town that Duncan is originally from, especially at a particular pub where Duncan's mom worked as a prostitute. Hickey mentions losing his virginity to one such prostitute, around the time Duncan would have been conceived. An awkward silence follows until Hickey mentions that the woman he slept with only had one thumb. An extremely relieved Duncan says that his mother still has both her thumbs. He does, however, have an aunt with one thumb, and his cousin's personality is a lot like Hickey's...
- On Just Shoot Me!, Maya begins dating the son of one of Jack's old friends. However, it turns out Jack had an affair with the friend's fiancée right before the wedding, and he realizes that it's plausible he is the guy's father. It turns out his father secretly obtained some of Jack's DNA years ago and got a paternity test. Maya and the guy, however, are horrified to learn that they might be half-siblings.
- The tenth and final series of Spooks featured Sasha Gavrik, a Russian FSB operative whose father was either Ilya Gavrik, the lead negotiator in the proposed partnership between Russia and Britain, or Sir Harry Pearce, who'd gotten sucked into the intrigue surrounding The Parnership due to his connection to Elena Gavrik. Sasha himself doesn't know of this upon his initial introduction, and finds out via a secure file in the fourth episode. The final episode has Elena reveal that that she knew Ilya was Sasha's father, and that she deliberately complicated the situation in order to further the goals of the KGB (back in the 80s) and later the Ultranationlist faction that was trying to sink The Partnership. The revelation leads directly to Elena's death at the hands of Ilya - which in turn leads to Sasha going after Harry and killing Ruth instead.
- An episode of Frasier had an old friend of Niles and Frasier's (deceased) mother turn up. He is much closer in personality to the sons than their father, and, thanks to Roz, Martin begins to wonder if he could be their real father (in no small part because Hester did cheat on him once). Eventually the friend confides that he loved their mother because she never revealed his big secret: he's gay (and obviously never slept with her).
- In Arrested Development, Oscar Bluth is certain that he's Buster's real father. He expresses this by constantly dropping laughably obvious hints which Buster is too Genre Blind and oblivious to notice. Lucille seems convinced of it too but since Oscar and George Sr. are identical twins it could be either way and not really make much of a difference.
- Jeremiah: Discussed with Jeremiah and a former lover of his whom he may have fathered a son with. She says that while she could try to calculate the date of conception, she's not going to make her son long for a father who can't be around for him, so we never find out if Jeremiah really was his father or not.
- In season ten of Trailer Park Boys, Mr. Lahey reveals to Ricky (in a coma) that he, not Ray LaFleur, is Ricky's father. The following season, Ricky discovers this and starts bonding with Mr. Lahey. Julian and Bubbles sneak into the hospital records department and check Ray's blood type and compare it Lahey, Ricky and Tammy (Ricky's mother). It turns out neither Lahey nor Ray are Ricky's father. They tell Ricky about Lahey not being his father but don't tell him about Ray.
- An episode of Airwolf featured a Vietnamese refugee who'd been in a relationship with St. John Hawke and her son who might have been his and thus Stringfellow's nephew. The episode ends with Archangel noting they might never know the truth.note
- Invoked in the Burn Notice episode "Sins of Omission": Michael's ex-fiancee Samantha states that her young son Charlie, whom Monster of the Week Tyler Brennan has taken Hostage for MacGuffin, is nine, making him old enough to possibly be Michael's, though she says he isn't. When they rescue him, Michael is quick to notice that Charlie is actually only seven.
Samantha: Told you he wasn't yours.
Michael: You let me believe he might be.
Samantha: So what? You never stretched the truth just a little bit to help an innocent person?
- Peacemaker: Played for Laughs when Peacemaker goes to a school presentation, and one of the girls askes if he knew her mother Becky Coolidge, and when Peacemaker says that he did the kid says he might be her father, which prompts the teacher to quickly end the presentation.
- The premise of Mamma Mia! is the female lead trying to find out which of her mother's three ex-boyfriends is her biological father so that she can ask one of them to walk her down the aisle.
- Final Fantasy VI takes this trope and stretches it as thin as it can get. A series of hidden flashbacks reveals that Shadow was injured at an unspecified point in the past and nursed back to health by an unspecified young woman in Thamasa. It's not even specified that they slept together, but the Law of Conservation of Detail (and a cute doggy) suggests that the woman was Relm's mother, and Shadow is her father.
- Another popular theory holds that the Memento Ring relics are evidence of a connection between Shadow and Relm, as only those two can equip it. Relm has one initially equipped, and you can find another hidden in Strago's house. (You can actually steal a third ring from Wrexsoul, but that's neither here nor there.) Its flavor text mentions a mother's love acting as protection from fatal magical attacks.
- Kiros and Ward's comments on Squall in Final Fantasy VIII consisting of "Glad that you didn't turn out like your father" and "You look a lot like your mother", and the backflash says that Raine died after giving a birth to a baby. Who Squall's parents are isn't said outright, but it's most likely Laguna and Raine. Since Laguna's still an Idiot Hero no matter how many years has passed.
- In Umineko: When They Cry, with the revelations that Kyrie apparently had a stillborn child on the same day that Battler was born and later that Asumu is not Battler's mother, it's heavily implied from EP4 onwards that Kyrie isn't Battler's stepmother so much as his actual mother. This is later confirmed in EP8.
- Metal Gear Solid: Peace Walker heavily implies, although never outright confirms, the possibility of Strangelove being Otacon's birthmother in the second ending due to apparently expressing an attraction to Huey. This is confirmed in Metal Gear Solid V: The Phantom Pain. Albeit, Strangelove states that she purely used him for his body and raised Hal as her and the Boss's child instead, but this is from a deathbed monologue after Huey locked her in the AI Pod to die, and may not be an unbiased account of Huey.
- Dead Secret has Josie Herrera moving in with Harris Bullard, because she is secretly trying to determine whether he is her biological father, who left her mother for the military years ago, or just happens to look similar to an old picture of him. The various notes in the game, as well as Harris Bullard's secret, does reveal that he is her long-lost father.
- In the post-storyline portions of Pokémon Black and White, a parental relationship that was thought to be clear is called into question. One of the captured Sages of Team Plasma recalls that he doesn't know where N came from, and speculates that Ghetsis might not be N's father. Considering what Ghetsis was doing to N, this might even be more horrifying.
- Dishonored strongly implies that Corvo was the Empress' lover as well as her bodyguard, and Emily is his daughter. Word of God eventually confirms that Corvo and Emily are indeed father and daughter.
- A persistent fan theory among the Guilty Gear fandom is that the identity of Dizzy's father is none other than series' lead Sol Badguy. This is mainly because, back when he was still a human named Frederick, Sol was romantically linked with a fellow scientist named Aria, who is heavily implied to the true identity of Dizzy's mother, the Commander Gear Justice, although the timeline muddies things due to Dizzy's suggested parentage both being full Gears (Dizzy is only half-Gear) and having a mutually antagonistic relationship around the time Justice would've likely given birth to Dizzy. The guy in question does have an odd but subtly paternal way of dealing with Dizzy (his Story Path 2 and Dizzy's Story Path 3 in XX are two of the most frequently-cited examples among several), never mind some shared powers that are too coincidental to ignore, but like many things in Guilty Gear, it's been left deliberately open until further notice. If true, this would also mean that Sol, already a mentor and father figure to Sin, is the boy's actual grandfather, as Sin is Ky and Dizzy's son.
- Far Cry 4 drops some clues, particularly in Ishwari's diary, that Ajay might actually be Pagan Min's son instead of Mohan's. The game itself never gives a straight answer, though Word of God Jossed it entirely in an interview claiming "No, Ajay is not Pagan's son. That twist is stupid."
- In Fallout: New Vegas, a male Courier with the Lady Killer perk has a brief moment of this when meeting the Lonesome Drifter, who comes from Montana in search of his Disappeared Dad, who walked out on him and his mother when he was still a young boy. At this point the Courier can nervously ask the Drifter if he wouldn't happen to be 17 years old (he isn't).
- Something*Positive made a Cliffhanger out of Davan's one-night stand with Donna, insinuating that he might be Rory's father. He wasn't, but still acts like a father figure to him.
- The Trope Namer was a Penny Arcade comic where Gabe discusses with Vader and Yoda that Vader might have been his father, with Vader expressing embarrassment about the possibility, and Yoda insinuating that he'd slept with her himself and that she Really Got Around.
- Epic Rap Battles of History used this in the first Vader vs Hitler battle.
Vader: So many dudes been with your mom, who even knows if I'm your father?
- Noob: La Quête Légendaire manages a female version in which the mother got amnesia, shipped to a psych ward and separated from the child. The father is a Forgetful Jones who's implied to have a busy love life, so he can't remember which one among three sons, that include one of the protagonists and a regular character, that specific ex gave birth to.
- At the end of the DEATH BATTLE! between Agent Carolina and the Meta, Sarge mentions that he has a son. Boomstick then mentions that his own Disappeared D Ad joined the military. Sarge finds this so unsettling that he leaves the scene without pursuing the subject.
- South Park two-part episode (with Cliffhanger) "Cartman's Mom is a Dirty Slut/Cartman's Mom is Still a Dirty Slut" - Cartman tries to find out who his father is. The thing is, Mrs. Cartman was really drunk that night and while she almost had sex with just about everyone at the party she was attending (except Halfy, but he doesn't have any legs so he doesn't count), she can't quite remember who she finally ended up with. The two-parter ended with the revelation that she's a hermaphrodite and Cartman's father, with the mother now unknown. However, a much later episode Ret Cons this to say that his father is Jack Tenorman, the father of Scott Tenorman, making Cartman a Self-Made Orphan.
- Parodied in Home Movies. The kids' new film feature Brendon and Jason playing two convicts who escape from prison to see their daughter (Melissa). When their daughter asks which one of them is their actual father, the two respond that there is "no way to tell" because they both had sex with her mother "in the same room, at the same time."
- In the Adventures of the Galaxy Rangers episodes "Gift of Life" and "Sundancer," the disgraced Fatherly Scientist Max Sawyer asks Shane (an Artificial Human that Max helped create) to find Max's son, Billy. The kid appears to be ordinary, and Max did have a wife. However, during the climactic horse race, Billy appears to activate Supertrooper-like abilities. Seeing as Max Sawyer was a genius at genetic engineering, it leaves open the question as to whether Billy was conceived the natural way, or if the kid is really Shane's de facto brother.
- In an episode of The Simpsons, Homer meets one of his mother's old flames and starts wondering if this man, and not Abe Simpson, is his real father. A DNA test proves that this is the case because Abe switched the labels on the samples, wanting Homer to have a father he could be proud of.
- Used on Archer, who has at least three potential fathers. The one most interested in building a relationship with him (and at least trying to prove his paternity), and thus falling into this trope, is the head of the KGB, Nikolai Jakov. Though DNA testing exists, his sample was deliberately contaminated when tested by the KGB. The other possibilities are rival spymaster Len Trexxler and jazz drummer Buddy Rich, though he is apparently the least likely. A fourth man was revealed to have had an affair with Malory just before WWII, but was executed for speaking out against fascist Italy. When Archer runs away following his fiancée's death, his mother sends Rip Riley to find him. Rip eventually reveals he had an affair with Archer's mother, but Archer would have to be 15 to be his son.
- Parodied in Bro'Town - Jeff da Maori does not know who his biological father is. He's probably one member of a biker gang, so Jeff just refers to all of them as "Dad". A few even show up to some school events.
- In an episode of American Dad!, Jeff Fisher joins the navy, the naval captain is oddly favoring and forgiving despite Jeff causing many a mistake. Turns out he believes Jeff to be a son via a woman he loved in port who looks a lot like Jeff.
- A Japanese law (now obsolete) barred women from remarrying for six months after a divorce in order to avoid this trope. On the other hand, if she was having an affair...
- In France, divorcées had to stay single one year.
- While not a legal requirement, social convention in 19th- and early 20th-century Britain held it unseemly for divorcées and widows to remarry within the year following the divorce/death.
- Similarly, Islamic law prescribes a waiting period of three months before a divorced woman can be married again; widows have to wait a little longer (four months and ten days), probably to be extra-sure she's not pregnant (which could cause all kinds of problems with the administration of the deceased man's estate).
- Identical Twin Brothers in Paternity Suit. In this case, determining the father would be impossible.
- Cracked did an entire article in December 2012 on societies with bizarre sex cultures which exist solely because of the inability for men to carry a child to term.
- Genghis Khan and his eldest son, Jochi, who was conceived around the time Borte, Genghis Khan's wife was captured by a rival tribe (he was fairly low in Mongol tribal pecking order at the time). The uncertainty over Jochi's paternity precipitated open conflict between his descendants and other Mongol princes and eventually tore apart the Mongol Empire.
- In 2013 the tabloids had a field day after Mia Farrow stated that Frank Sinatra, not Woody Allen, might have fathered her son, Ronan. Sinatra's daughters Tina and Nancy called the claim ridiculous, and said their father had a vasectomy years earlier. Since then, Farrow seems to have walked back the claim, which was conspicuously absent from the HBO docuseries Allen v. Farrow.
- Both at the time and throughout history there has been speculation that Julius Caesar may have fathered his most famous assassin Marcus Junius Brutus, as his mother Servilla was Caesar's favorite mistress, though as Caesar would've been 15 at the time it's unlikely. It's thought that he's more likely he fathered Brutus' younger sister Junia Tertianote , and one of his other assassins, Decimus Brutus, has been speculated by historians as being his son.