OK, so I'm pretty sure we all agree and know how this ends, if nothing changes.
What would be one or two things that, for you, would make the M at least more tolerable, if not better. I really want no more than three things. But please take whatever time you need to think about this.
It might be something like, H puts the toilet seat down every time, or H starts cooking veggie meals for me, or H plays with S in a way that S wants and does not hurt S.