I may be in the minority, but I would kick him out. The way I see it, he wanted to be heard and you heard him. He refused to admit to the A, blaming it all on you. Well since you talked to the OW, she's going to keep up appearances to "work on" her M. So right now your H basically has no one. He still holds you at night (more like a teddy bear) as security. He's going to continue to do that until he finds someone else.
It's his pattern. You've detailed it very well here. And the fact that he is always wanting to be in control.
I think the faster you push him to hit rock bottom, it might shake him up enough to see that what he has is better than what he "might" have.
Just my 2 cents.
M-43 W-40 2D - 9 and 5
Emotion, yet peace. Ignorance, yet knowledge. Passion, yet serenity. Chaos, yet harmony. Death, yet a new life.