If you haven't done so already, I think you should tell your wife in no uncertain terms that you have no intention of being good friends with her if she insists upon ending your marriage this way. Most waywards have this grand fantasy of everyone in their past and current life -- including their spouse -- being OK with their new relationship, and everyone holding hands and singing "Kum-ba-ya" and living happily ever after. When I told my wife that I would NOT be her best friend (and we've always been best friends) if she ended her marriage by way of an affair, it devastated her.
Consequences.
I also told her that I had NO intention of EVER letting OM be around our kids, and my MIL also told her that she would NEVER, EVER accept him into her life or her home.
The components of a good friendship -- quality time, words of affirmation, sharing goals, dreams, hopes, being there to console each other, etc. -- these are all "emotional needs" that get met. To my way of thinking, those are bundled up along with the more intimate needs that a husband and wife share -- they are a "package deal." If your wife sh*ts on the one, she shouldn't get the others, and she should know that.
It was this missing of my friendship and companionship more than anything else that caused my wife to end her affair, in my opinion. That and the pressure brought to bear by her parents and our adult daughters, to whom I exposed her affair.
