I know it feels hopeless. Unless this affair ends, it is. You can't make him quit, but you can do things that make him reconsider what he's doing.
He IS acting like he has a free pass. Know why? Because he does. He knows you are desperate for him so he can do whatever at the moment and if he gets tired of OW, you are right there waiting. If he told you tonight that he's committed to the marriage, can you even say there would be a moments hesitation or that you'd even insist that things be over with OW?
For your own sanity and peace of mind, I will repeat that you should do some things to make it clear to him that you don't approve of this behavior and are not only capable of moving on without him, but willing to. Start with the separation in the same house. Start by reminding yourself that you are a catch. You absolutely DO NOT have to play second fiddle to some woman that would be with a married man. YOU are too good for HIM. Him chooses this trollop over you is HIS loss and not yours. Would you even date a man like he's being at the moment? He has a lot to prove to YOU. Start working to be the woman he'd even be more crazy to leave...and that doesn't mean walk on eggshells or kiss butt. Self-confidence, self-esteem, and unobtainableness are very attractive. Be your best, but don't let him have you. Make him earn you.
In the end, it's not the years in your life that count. It's the life in your years. Abraham Lincoln
It is hard to fail, but it is worse never to have tried to succeed. Theodore Roosevelt
