Bono, the front man for U2, once said that karma is the law of the universe: what you put in you get out. Your husband and OW will get what's coming to them, so to speak.
But, Bono, added, the only thing in the world that upends and cancels out karma is Grace. If Grace touched your husband's life, it would not give him merely a "get out of jail free card", but rather, a new heart. So I pray grace would touch your husband's heart, which would, then, cause him to truly and deeply repent.
That's rare for me to dish out these days, since I'm so pissed off and angry. Me praying for your husband? Take it as a small miracle. ;-)
Here's an interesting quote by Simone Weil, a French philospher:
Evil, when we are in its power, is not felt as evil, but as a necessity, even a duty.
Kind of explains some of the WAS's behavior, doesn't it?