Slowly, I haven't been around for awhile and I have caought up on your thread. It seems to me that your H wants you or QW to give him an ultimatum so he doesn't have to make the decision. He may keep up this charade as long as you and her allows him to. He doesn't want to hurt either one of you.
I can't give you any advice,but I fear if you give him an ultimatum he will run to her. Just some thoughts. Good luck.