One thing I wanted to add is that it sounds like he is projecting fear of abandonment onto you, I had/have(?) that same issue. Once I got counseling with EFT after BD, I am in a different place...your H needs some counseling to resolve that, his trust issues, etc.
The OP doesn't have the baggage from the R that we LBS do... yet....
He hasn't logically put together the fact that she worshiped and went after a married man with kids, thus her morals are ummm..."less than stellar", and what might she do when tempted down the road when H isn't Mr. Magic Man anymore...
That thought will eventually cross his mind, he will file it away under "denial", but the underlaying trust/abandonment issues will slowly fester away at his feelings towards OW, I reckon.
In the depths of winter, I finally learned that within me there lay an invincible summer. - Albert Camus
Uncertainty is the very condition which impels people to unfold their powers.-Eric Fromm
