I think if you engage with him about the OW, it turns into a battle between you and her, between him and you. If you withdraw and get out of the way, it means he has to battle with himself and decide what kind of man he wants to be. This is his problem. Obviously it affects you deeply - but it is his affair, his betrayal and his MLC. Let him experience it without your help and protect yourself from the consequences of his decisions.
