I think it's all in the presentation. If you callously say "You b%$#h, I'm leaving", you'll get one reaction, but "I can see this living arrangement is not healthy for any of us, and I feel we'd all be better off if I moved out" would elicit another.
Good luck
M:23 T:26 Me:53, Wife: 60 S:18 D:16 filed 7/16 W moved out 4/28/17