I think you're on the right track, Aud. I don't know how else you can handle it. I think it pointless bringing up OW, and whether he's in contact with her/them. He certainly does need to dig deeper than just "I care about you, so I'll stick around". He is a father, and needs to work on taking care of the things that make his children safe and secure, and that includes being faithful to his M, and his church, IMHO.
I guess you said it right when you said to expect the best, but prepare for the worst, especially since he's been a somewhat serial cheater. I do wish he would go see the church leaders, but maybe he's not in the right place, spiritually. So, patience is the key here, and I think you have loads of that. And, just enjoying having your family together.
Me:57 H:52 M:28 Got another lawyer last year and filed. D35,S/D twins28,D22 EA4/04 End? Who knows? "Life is like a mirror. Smile at it and it smiles back at you." — Peace Pilgrim