If people can handle the emotions tied to it, and be able to still control their feelings and GAL like they need to, I always advise not to kick the other person out. The more time you are able to show the WAS your changes, the easier and faster it will be for them to believe it and want to come back.
He's not going to be able to control his feelings when his wife announces to him that she's flying to another city to hook up with her boyfriend. It's emasculating, it's emotionally abusive, and she's losing respect (and therefore, LOVE) for him every day that he tolerates it, in my opinion.
I do generally agree that if healthy boundaries can be maintained, that it's best to remain together, so that the LBS can live out their positive changes in front of the cheating spouse. But it has to be a question of DEGREE. At SOME point, it's not healthy.
