Law of Skins

Pertaining to the British show Skins, this law dictates that any two characters in a drama of a sexual nature shall, at some point in the current episode or next, engage in intercourse.

*Tony and Effy appear on screen*
Guy 1: "They're gonna bang"

Guy 2: "They're related!"

*Later in the episode "Now fuck your sister!"*
Guy 1: "Law of Skins!!!"