Similar to being sexiled, except the reason you can't get into your rooom is that your roomie is enjoying some single player entertainment.
Matt: Hey let's go play Scrabble in your room.
Jill: My room's on the other side of campus. Can't we just use yours?
Matt: Well, when I walked in to get the board, William was under the covers with a box of tissues on the bed. Which is to say I think he's busy.
Jill: And were totally using my room.
Amy: Why didn't you guys just play in Matt's room?
Jill: Um, his roommate was busy.
Matt: We got masturbanished.