LWB, Some (((hugs))) from me, too. You may not feel proud at having the scream fest, but holy crap you have been patient for so long. It does come down to a matter of respect. After taking you out the other night, then having a date with OW tonight?? You had every right to explode.
I hope you found a way to be out with your Ds when he came home. I sure would go dark, dark, dark on him -- for your own piece of mind. Like everyone else said, you need to detach!! No matter what was said, or yelled, etc. there is no way he is out tonight with a clear conscience. No way no way no way.
I hope you're doing ok. It's hard to function normally when you know your S is with OW/OM. I've been there, too. Keep focused on your D's. (And OW was mad at her H for telling you and hurting you? GIVE ME A BREAK! Like he is the one doing the hurting. Alien.)
LWB, you're such a considerate, compassionate, kind, decent person. None of should have to live through this crap, but when the journey is over, we'll all be better, stronger, wiser human beings. But boy the road sure is tough.