Sometimes it's useful to think about what that would look like. If you separated/divorced, if he spent a year going to therapy and making his life 100% transparent to you, if he called OW with you on the line and told her he wasn't going to have any further contact with her and that he regretted putting his marriage in jeopardy over her?
Remember, if he's REALLY sincere about wanting you back, he would do all these things, and separation or divorce would not deter him. I think your bullsh!t meter is correct and he just doesn't want to have to deal with any consequences of his actions - as evidenced by his lack of true remorse, he keeps trying to put the blame on you.
