I'd say they were BOTH behaving trashily. He was one who said vows, not her, which is true. So he was trashy. And she was a willing participant in taking up with a man who had made vows to another woman, and that's pretty trashy, too.

A man of integrity would not do what he did.
A woman of integrity would not do what she did.

I'll take a Duggar over people who behave like that any day.