Yes I think I would have to leave him if he did it again. I dont believe in cheating of any kind. I would never cheat on him no matter what, but that's just who I am. She is a sex addict. I dont know why she did it but she is definately out of our lives. There is no chance it will happen again with her. No, we were not fighting when it happened. I thought everything was great. We were getting along & no problems in the bedroom either. He has no excuse except that she offered & he took her up on it. He said he hated himself the minute it was over. She did stalk us for a while but hopefully that wont happen anymore either. She is psycho. She told her husband about it but turned it around so it looks like we are the bad guys. She tells him enough of the truth so that he believes her.