Luke, I Might Be Your Father

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.

An Always Male trope, as it is predicated on Mama's Baby, Papa's Maybe.

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.

Examples of Luke, I Might Be Your Father include:

Comic Books

• 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.
  • This also happened in one of the Conan movies.
• 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.

Film

• 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.
  • Rob is also pretty awesome and pragmatic about the whole thing; he points out that the child is innocent in it all, and accepts it either way.
• Men in Black II. It's heavily implied Kay 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).

Literature

• 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 concieved 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. 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.
• 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, a Reverse 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.

Live Action Television

• An episode of Dharma and Greg featured Dharma becoming convinced that Greg was the father of his ex's son. It's all a big misunderstanding.
• 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.
• 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.
• 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 this trope is in play with Judith's pregnancy. The show still has yet to reveal if it is...
  • 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 (with Charlie's mom being heavily implied to have potentially given birth to her from an extramarital affair with one of her old friend's husbands). This ended up having Charlie's bar on who to sleep with raised somewhat.
• 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. It turns out he's not the father, though.
  • 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 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 seven sixty-three men; who's my baby's daddy?" In fact, "You are / are not the father!" is practically his Catch Phrase.
• 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.

Theater

• 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.

Video Games

• 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 looks a lot like your mother.", and the backflash says that Raine died after giving a birth to a baby. Who's Squall's parents aren't said outright, but it's more likely Laguna and Raine. Since Laguna's still an Idiot Hero no matter how many years has passed.
• In Umineko no Naku Koro ni, 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.
• 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.
• 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.

Web Comics

• Something*Positive made a Cliff Hanger 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 embarassment about the possibility, and Yoda insinuating that Gabe's mom was a prostitute.

Web Original

• 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?

Western Animation

• South Park two-part episode (with Cliff Hanger) "Cartman's Mom is a Dirty Slut/Cartman's Mom is Still a Dirty Slut" - Cartman tries to find out who his father is. Turns out it's his mother, because she's a hermaphrodite. When they try the same trick to find out who his mother is, he says, "Screw it! I don't wanna know!"
  • Later it turns out that Cartman's mother actually is his mother. Cartman shares his actual father with Scott Tenorman, making Cartman...
• 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 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 climatic 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 concieved 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.

Real Life

• 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, she had to stay single ONE year.