Jp, my approach was different. I learned about the OW and I almost broke. But the really cool thing was, I didn't. There was a very small thin steel core to me that bent but did not break.
When I rose, I truly understood a few things:
I cannot make any one else's choices but my own That H having a GF was not a deal breaker for me That people come into lives for a reason.
H left and found a GF so fast your head would spin. But like your wife, he needed it and like everyone says, it was a way to avoid dealing with all the emotions leaving brought for him.
He loved her, wanted a serious relationship, so i Iet him go. Four weeks later that relationship was over. I gave him basically my blessing because above all I wanted him to be happy.
But guess what? When you don't figure out what happened in the first relationship, you sure as heck are going to repeat the behaviours in the second.
So what I am saying is you made your choice to lay down an ultimatum and she will make hers. But the need for support from OM will continue until she realizes that you can be strong, you can carry on and she can lean on you if she had to, because she sees the kids being able to take their strength from you.
You're going to have to pick yourself up now. Ultimatums given in a kind loving way describing a boundary for you is attractive and masculine. Giving an ultimatum and then apologizing for making her choose is not.
