Mom and Boyfriend fighting..

I don't want to go into too much detail. My mom got a boyfriend and she hardly comes home anymore. It leaves my boyfriend and I with the house and animals to take care of ourselves. Now were 18 and 19 years old so it's not like those are things we can't do or shouldn't do. But it's just that she leaves us with HER house. Its been going on for a long time now and my boyfriend said something to her about it, that she needs to help too and we shouldn't have to do everything. So now they keep talking bad about each other and I'm stuck in the middle. Moms screaming and calling him stupid and talking bad about our relationship because we've had problems in the past and are still working on them. Boyfriends talking about how she doesn't do anything or help us out and just complaining about her. I don't know what to think, I don't know if I should be mad at my boyfriend for getting into it or not, I know he was just trying to help but it's created so much drama for me. I just want them to stop talking bad about each other and all of us to just be happy again. They're both so hard to sit down and talk with, they get mad all over again and then the problem stirs back up. Please just give me advice.