Why do you say that? Her husband truly loves her and has never done anything to deserve being betrayed and abandoned.
I hope she comes to her senses and goes back to her husband.
Life isn't just about sex; it's about love and companionship
Why do you want him to stay with someone who is clearly checked out from that relationship?
Woman is so checked out she actually believes her sexcapades as a teenager were better than the sex she's having with her partner of years. She's so checked out she instantaneously went and fucked her best friend even though she had never being with a woman before.
The best thing that could happen to him is to be freed from someone who clearly doesn't care about him anymore. As you said, he has done nothing wrong, and he doesn't deserve to be betrayed (no one does) or having such a shitty partner.