Shame is powerful but not destructive, it is part of the glue that holds society together. Unfortunately we have done everything to eliminate shame.
The man in this relationship is most at fault and I hope he gets what is coming but knowingly being involved in the situation is almost as bad. Additionally the fact that she is basically doing it for the money makes her part of the oldest profession.
I've known some guys whose wives turn into absolute bitches over time. The father of a girl I dated for a while in college was one such person.
He was a great guy, worked hard, made good money...and had nothing but an angry resentful wife to come home to.
I used to think how much better his life would be if he had a woman on the side who simply showed him a little kindness and affection. As far as I know, he didn't.
He was Catholic BTW and divorce was out of the question.