I too would like to hear the answers to some of the questions above.
And I'm going to tell you something that may not make total sense - at this point, the best chance for your relationship is if you move on with your life. IF he has the capacity to recognize his failure, get the counseling he needs to not become a repeater, and beg your forgiveness - you can make a decision at that time about whether you want him back. But that is less likely to happen if you are waiting around for him as Plan B. It's actually more likely to happen if he THINKS he might lose you. (Note - I'm not suggesting you actually date at this point, but letting him THINK you might be dating doesn't hurt. You can stage some things at the house for when he comes over - roses in a vase - when he asks, they're "from a friend, you don't know them". Sexy lingerie drying in the bathroom. )
All that being said - think carefully about whether you even want him back. If he'll do this now, at this point in the relationship, what use will he be when things get truly difficult? Is he someone you could count on when, say, your child develops an eating disorder or a drug addiction ? (Both things that happened with my kids). Would he just cheat again in the future, hurting your child even more?
