I think the bomb you drop on him will be that you agree that it's time to D, but it will not go as smooth as he thinks.
"I have kept cooking, doing the laundry, etc., trying to maintain a house and home that you would appriciate. I realize that I was only fooling myself. Thank you for getting the ball rolling on the D process. I have interviewed a couple of lawyers and will retain one of my choosing to respond to the papers."
No more Mrs. Nice Guy. It's time to make him see and feel what he is doing and that it won't be easy.
