Betrayal is in your mind! time for a little Zen break from our destructive ego-centric world...
The "cheating" aside, everything else that has been shared about this guy does not bode well for a healthy relationship, no matter what the expectations are - and even worse for the kids involved. The worst thing to do to kids is stay in a destructive relationship...
Betrayal isn't in the mind, betrayal is an emotional response which is not in the logical/rational mind, they have a lif of their own.
Betrayal isn't having sex outside the marriage, it is having sex outside the marriage behind the other person's back, and worse, from reading the OP's posts, he also doesn't exactly seem like he understands what a big deal this is (I could be wrong, since I only have the same info as everyone else). Based on what the OP has written, it wouldn't surprise me if he is still cheating, or planning to.
your way.