My question is, how does a guy sit back and have his girlfriend or wife have another guy come stay at your house over night? On top of that, stay up all night, every night, with the guy and NOT realize she is banging the guy! If my wife told me she was bringing some guy home to sleep at our house, I would first refuse to allow it. Then file for divorce. There is no way in that scenario, your girl isn't getting banged by the new guy! They are NEVER just friends!