As for telling on her to the MC, what's the point? It seems like you really want to tell the MC what's going on. The MC's have more experience than us, they know how these things work. The counselors know they are being lied to a lot of the times, do you think that she's going to tell your W to stop lying and that your W would listen? There are business and clinical reasons not to do that.
Just tell your W you won't be with a woman who is an affair. If you do that, it's probably time to kick her out. She is disrespecting you and your family and your marriage. And did you ever out the OM to his W? I know you and him had some discussions before.
And if you can't kick her out or tell her/show her you won't be with a cheater then just go to the moving on part without saying anything.
Then move on, go out with buddies, play sports, go hunting, enjoy your newfound freedom like you were a single guy again. Talk to women, go on adventures, whatever you like.
H 34 W 29 BD 3/12/18 Divorce Busted Spring 19
It is not things that bother us, but the stories we tell ourselves about things.