Should I move out?!?! NOW?!?

My SO and I have been together for 11 years. 😩 We have lived together for most of those years...about 2.5 years ago he bought a house and his mom asked could her and his baby brother move in until she "got on her feet"...it's been 2 years and he and I are the only ones working and paying the bills even though his mom and brother are fully capable of working/contributing. He gets pissed bc she will have people all in the house spending the night that he doesn't know. The other day there were 7 vehicles in the driveway blocking him from parking in his own $8,000 renovated driveway. He had to park on the street and was livid. But didnt say a word, yet we ended up in an argument bc I told him to tell someone to move. His 18yo brother has barged into our room while I was BUTT ASS NAKED multiple times "looking for something" and doesn't see anything wrong with it. Awkward af. Also, started an argument. I was COMPLETELY naked....I've walked into our room and she's in our bathroom "cleaning" and going through cabinets and drawers bc she thought no one was home. Totally in our personal space. I'm not used to that. We've lived alone for years. It pisses me off bc he has told me these things upset him yet he won't confront them or say anything to them about it. They stay on the opposite side of the house but as much as he tries to convince me that it's OUR house and OUR life, I'm so uncomfortable that I just hole up in our room all day to avoid confrontation bc I get so angry. Then she tells him that I'm anti social...out of respect, I don't say shit but it's really annoying that he will voice his frustrations to me about it but he won't stand up to her, especially when he's just as angry and uncomfortable as I am and feels like she's possibly taking advantage of him...I'm almost to the point where I want to just move out but I know that would crush him and put a stain on us..And I would in NO way give him an ultimatum between his mom and I, but I'm not happy living there with all of this tension and awkwardness. what would you do?