I do remember you saying that if ever there was any future evidence of him getting back with OW that that would be it for you.
You might want to visit with your pastor to see what he has to say about the latest.
I think your lost H is being unconciously manipulative.
He kind of reminds me of my daughter this weekend who I warned multiple times to behave. Then, when I enforced the consequence, I heard nothing but "I promise to be good. I really will. Give me another chance."