Couch Theory

This is the official term to describe that moment when someone walks near, into, overhears your conversation at the worst possible moment, even if the subject is benign.

Person A: So I was watching this movie yesterday, and there was this hooker snorting a line of cocaine of the table.

Person C: Whoa! Hookers and Cocaine? What did I just miss?

Person B: Nothing, dude. Just proving the Couch Theory.