I don't know. My only thought is that it cold be emotional? Maybe he is just looking to break rules by cheating or seeking something outside of the marriage, which, I don't know how you resolve that except through roleplaying early on. At this point, he's been caught, so it could just be that he's having second thoughts or can sense that you're still emotionally distant. I would suggest marriage counseling, but only if he can be honest and actually cares about working on this relationship. Maybe he's not ready/willing to do that. I don't know.