I know it hurts and part of you feels better by delivering the blunt truth to her, but it makes you look a bit petty and vindictive (not that you don't have reason to be).
You feel helpless. Of course you do. You are JUST now facing the reality that your marriage may be over. This marriage at least.
My guess is that this is a woman who will not be changing anytime soon. She has quite a track record with you long before this most recent betrayal. But that doesn't mean that you HAVE to choose to give up on her.
Whether you remain alone or choose to move on, complete with the possibility of another one day, is totally YOUR choice.
The bottom line is that hanging on to her right now will only bring hurt.
And honestly, I think your most effective course is to be honest with the situation, establish some stern boundaries regarding the children, and ALLOW yourself to find some peace and calmness again. By letting go of her NOW, you allow yourself to heal and prepare yourself for whatever the future might hold.
Letting the WAS get away with inappropriate behavior in the hopes of a restored relationship is humiliating. My guess is that they KNOW we are allowing them to abuse us, and it only strengthens their belief that we are not the ones for them.
I'm terribly sorry for all you're going through. But I also know that you are quite strong enough to come through it a stronger and better man.
Blessings,
Bill
"Don't tell me the sky is the limit when there are footprints on the moon."