Wow! This sounds VERY similar to the position that HMA, Anne, and I are in. I hope he's able to give you some insight. Time management is one of the biggest things we struggle with in our triad. HMA and I live and work together, while Anne lives nearby but not with us. We see her several times a week, but it's always sometime after 7pm; and working around her school schedule/work schedule. It can get REALLY hectic.
I'll ask a couple questions of my own so maybe I can give you some insight too, because I've been right where you are - feeling neglected, irrational, etc. lol It's an uncomfy as hell place to be!
Who is it you're married to? H or M? Or are H and M married?
Who do you live with? Or do you live on your own?
What is it that's caused your chats to be "explosive" as you put it?
Have ALL THREE of you sat down and talked about this, rather than dealing with it one-on-one?
There's a solution to every problem. Once I understand a bit better, maybe I can help!