The odds that a given character is the biological father of someone whose paternity is unknown is directly inverse to how badly the other parties directly concerned want him to be the biological father.
Or, to put it in plainer terms: If it is strongly hoped that a given character is the biological father of a character of unknown paternity, he probably won't be. If it is strongly hoped that a given character isn't the biological father of a character of unknown paternity, he even more probably will be.
A Sub-trope of Who's Your Daddy?
, although it may also be coupled with Law of Inverse Fertility
if it comes into play early enough.
So, Alice is pregnant and caught in the horns of her Triang Relations
- she doesn't know who the father is. So, after sufficient tension has been built up, she discovers that her baby's dad is not Bob, her
and the fans'
one true love, but Charlie, the hypotenuse — her worst nightmare. The law applies to the men too: Bob will hope he's the father before anyone knows for sure and be disappointed when the truth is known, while Charlie will have much stronger misgivings than Bob(often treated sympathetically) about taking on the responsibilities of fatherhood.
Anime and Manga
- In Nana, after starting a relationship with Nobu, Hachi sleeps with Takumi then discovers she is pregnant. Since she and Nobu practiced safe sex, Takumi must be the father, so she ends up with him.
- This came into play in Snow Dogs (starring Cuba Gooding, Jr.). Our protagonist goes to Alaska to find his real father. He develops mutual hate at first sight with an old and mean dogsledder. Unfortunately, circumstantial evidence suggests that this fella is his father, for various reasons, including a shortage of plausible choices and a mutual liking for blue cheese. And it turns out to be true.
- In Juliet Marillier's Son of the Shadows, Eamonn tries to pull this, telling Bran (who has trust issues) that Liadan's son might be his. However as the audience knows, Liadan never had sex with Eamonn, and by this point Bran is learning to trust more, and Eamonn's ploy does not work.
- Played with in Something Positive: Davan doesn't want to be Rory's biological father, but while he's willing to step up, the other (unnamed, unseen) guy isn't. Even when Davan is cleared by a DNA test, he becomes Rory's Parental Substitute anyway. He later says that in retrospect, he tells his girlfriend that he wishes Rory was his son; not long after that, Rory asks if he can start calling Davan "Dad."
- Subverted in Futurama: Kif's species can get pregnant just by coming in contact with another's DNA; the person whose DNA he assimilated (Leela) wasn't his first choice, but at least it wasn't Zapp Brannigan. However the parent, or smizmar, is considered to be the one who got them turned on into DNA assimilation mode in the first place, who in this case happens to be Amy.
- Used in the movie Bender's Game. The father of Mom's son Igner turns out to be none other than Professor Farnsworth, one of the smartest men in the universe, who is constantly complaining about how stupid Igner is.