What I have seen work is when the H dumps the WW. Whether in his attitude, behavior, or legally. I use the word "dump" for a reason. It is much more effective when he dumps her, rather than him trying to survive what she does to him. You know how it affected you when you got the bomb drop. Well, that describes how she feels to see you actually dumping her. But it must be legit, b/c pretense doesn't work very well. Not only for him to dump her.......but to show no interest in her at all, and him living it up.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!
