As long as you show how weak you are by allowing your wife to share herself with two men you are doomed.
I GUARANTEE you that she isn't going to come back and dump the OM as long as you allow her to cake eat. How silly of you..
You want to prove to your wife who the better man is?
Then show her how much you respect yourself by SHOWING her that you love yourself enough that not only will you let her go, but that you think it to be for the best because three people in a relationship doesn't work.
The guy that will win her here is the guy thta shows her he doesn't need her.... I would take my chances on being that guy.
I can't recall the last time I saw a reconcilation happen when the BS fought to be the better man. It doesn't work.