BM - sometimes it's easier for people to "appear" that they're moving on - makes it easier to not have to face what's happening, or what they're doing.
Have you read the books? What have you tried? What things does she complain about in the marriage?
....Understand, that I can't, not be what I am I'm not the milk, and Cheerios in your spoon ~ Avril Lavigne ~ ..."Nobody's Fool"...