Germain's Law
Similar to Godwin's Law, Germain's Law states that, in an argument/debate/slanging match, the first person to reference the other person's mother automatically loses.
Guy 1: You totally stole that from a bumper sticker.
Guy 2: It wasn't from a bumper sticker, it was your mum's ass tattoo.
Guy 1: Germain's Law!
Guy 2: It wasn't from a bumper sticker, it was your mum's ass tattoo.
Guy 1: Germain's Law!