I could be wrong, but I think what Sandi is saying is that you cannot control what your H decides to do. You can set your boundry that you will not live in an open M, but it is ultimately your H's choice what to do. How will you set your boundary around this? Saying "let" your H date sounds like you are controlling the situation.
Me: 42 H: 40 M: 12 H moved out - 8/2015 I filed - 8/2015