To suddenly shift from being warm, friendly, outgoing, and even loving, to being stand-offish and out of touch without any observable (or reasonable) trigger. Usually occurs in the early stages of a relationship.
A: So did butt-knocker call you today?
J: No, haven't heard from him.
A: Since when?
J: Since, like, three days ago.
A: What happened? He was like, totally stalking you. Did he just, like, go polar or what?
J: Let's smoke a bowl and eat some Scoops.