My friend was watching Dr. Phil yesterday...he told the wife in an affair situation..."why are you waiting for someone else to decide YOUR life?". That's a great perspective!
I couldn't agree more.
The way I heard it phrased once was, "Why are you letting the ONE person who DOESN'T have the marriage's best interests at heart right now, decide its COURSE?"
That's not to say you can control the outcome (you can't). But you can certainly control YOUR end of it, and adopt a "This is what it would take for me to even BEGIN to think about taking you back, but in the meantime, I'm moving along with my own life", confident, GAL stance. It doesn't mean you have to FILE or anything (altho, eventually, that day might come when you have to, if he continues to cheat). It just means you've adopted an air of "I've moved on, emotionally."