a retroactive law, a law that retroactively changes the legal consequences of acts committed or the legal status of facts and relationships that existed prior to the enactment of the law.
Guy 1: I just murdered dat bitch for facing me!
Guy 2: Damn! Dat Dumb fuck Bush just laid down a law 'bout dat shit!
Guy 1: Motha fucka!
Guy 2: Shit! You is screwed--dat law is ex post facto!
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi