I'm going to disagree with the others because I think you're getting into a legal issue here. YES IT SUXX to have her in the same bedroom when she's cheating, but legally she has as much right to be there as you do. You simply can't eject her. You CAN ask her to leave, but you CANNOT legally kick her out. This is a response a lawyer posted to someone who asked this same question on a law firm's web site:
Yes and no. Are you required to sleep with him - NO. Are you required to have relations with him - NO. Can you kick him out of the bedroom - YES. IF however, he refuses, well then YOU remove yourself from the room. You have no greater right to the room then he does, so you do not want to be charged with any type of domestic violence. IF you get to the bedroom first, lock the door. If he breaks down the door call the police. IF he is in there first, and refuses to leave, then YOU may have to sleep on the couch. Good luck .
