Have you thought that maybe he won't tell you everything because he loves you and wan't to hold onto his marriage?
I'm not condoning what he did, far from it. However i think it's ok everyone saying walk away etc, but it's alot tougher when it's actually you yourself in the situation, especially with kids involved.
If you both really really want to, you can get over this- however, obviously this will involve more from him than you. He has a helluva way to go to regain any kind of trust with you again.
Whichever you decide- I really hope that you can once again be happy.
Boo
xxx