My dad and step-mom are fighting… Again :/

I’m old enough that it doesn’t scar me, but it makes me so sad that my dad can’t find happiness in any of the women he’s married. Things start out great and degrade. We all moved into a nice house together, and I am afraid to think of what would happen if the two decided to divorce. I can live with my mom if we get kicked out as I have been for a while, but where would my dad go? I just want him to be happy.