First off, breathe. He may or may not discuss this with you tonight. If he does, listen. Don't be thinking about how you're going to respond to what he says. It's ok to take it all in, validating if you uderstand etc. and then tell him you want to think about all that he's told you and you'd like to talk again. Then really think about it. That he may be ready to go doesn't mean he doesn't have valid points that need to be heard. I know you do too, I don't think now is the time for your turn.
