GTO, FY gave you great advice. Your H is clearly not sure of his path because:
1. He hasn't filed.
2. He's supposedly not sleeping w the OW.
3. He says he's living like a "M man."
I think that, as all WAS's, he is not aware of exactly what is prompting him to want to leave. He is probably afraid and feeling not so great about himself. I think your detachment is helping the situation. Keep it up. And think that whatever happens will be in your best interest.