Re: I'm human please don't judge
It's to late to do what you should have done.
I do find myself wondering if she had something going on the side before she found out because the signs were already there.
Anyway, the marriage is broken, it was broken before but the repair of it now will take a lot more than I suspect your wife is willing to invest. She wants to separate because she wants to explore a relationship with the OM. If she comes back it isn't because she loves you it is because you are plan B and the relationship with the X didn't pan out (no surprise there, he is an X for a reason).
The funny thing about X's, it's easier to jump in the sack with them because they've done it so many times before that its no big deal. As soon as the A is exposed and they are public and no longer hiding, the danger and exhilaration go out the window and then they start to see each others warts again, the same warts that made them break up to begin with.
You have no moral high ground to stand on here as you are as bad as she is although like i said I suspect maybe something was already going on, now you've given her an out. All you can do at this point is stand back and wait for her relationship with her X to run its course while you decide if you are willing to be her plan b should she come back.
Our lives are a novel and we, the authors. if you don't like the story line, only you have the power to change it.