Then don't fight about it. I think you're perfectly within you rights to tell him, "no. If you won't float with me, I won't boat with you." End of discussion. Walk away. Don't respond to any more arguments for his choice.
Have you tried that?
M:63 H:53 S:41, SS:28, SS:25, SD:23 M:15 T:16
Bomb:12/17/11, "I think we should go our separate ways." H moves to his mother's house, 4/1/12 12/21/12: H moves back home, piecing