His asking the question indicates some damage, but I certainly think the answer to the question is important. I don't belong to the school that says that "lusting in your heart" is just as much an offense as doing the deed.
I'm surprised you are defending her H's irrational obsessions with ex-boyfriends from....what was it....15 years ago? Before they even got M? I don't blame zuzu one bit for not wanting to play into this insanity any longer. Her H sounds Extremely depressed and anxious to me.