SO snapped on me (long read I’m sorry)

So we decided to go out tonight with a group of friends. Per usual my SO invites his brothers. His brothers literally cause drama or problems no matter what each time we go out in some shape or form. Mind you I am also 25 weeks pregnant. So we go watch the fights which is just an event for amateur boxers and everything is fine. Everybody has a great night and right before the last fight his middle brother shows up (the other one was already there but he was not behaving poorly). We leave to go to a bar for a bit before we headed home so we could mingle with our friends that we don’t really see much because of me being pregnant. I’m standing outside waiting on my friends to finish up because they are ring girls. While I wait I’m standing with my roommate and my guy friend. His brother comes up out of nowhere and shakes my friends hand then starts pressing him and being rude. He’s coked out so let’s start there but when is he not? He says “what’s up you good? You sure you good?” And my friend responds yea why? And he says “you were on some weird ass shit last time so you good?” And just kept bothering him so I stepped in and said I think you’re reading too deeply into it. He snapped back at me and said “nah I’m not reading too deep” and walked off. Fast forward I walk to the other bar with my friend because I’m pissed off his brother is being rude to my friend. One of our other friends comes to the bar finally and I started saying what happened because I was clearly upset and my SO snaps at me for bringing it up. We start arguing so I just go sit in the car because I’m not about to be baited into an argument behind some shit your brother started. He eventually comes to the car and starts screaming at me because I brought it up. Literally any time his brothers do anything like that he takes up for them and nobody better say shit because that’s his family. Like dude grow the fuck up! If you don’t want people to say anything about your brothers check them or stop inviting them out. I’m a grown ass woman and yea if I feel inconvenienced or uncomfortable due to the actions of the people you invited I’m going to express that. It’s not like it’s personal secret family business. Your brother is a fucking coke head and chooses to start drama everywhere we go. His brothers JUST got into a fight with each other like 2 weeks ago one of them has literally shot at the other one and has pulled a gun on the other one multiple times. I cannot force him to not hang out with them obviously they’re his little brothers. I’d like to think he would choose peace and well being and take into consideration the safety of others especially myself when he invites them out. However nobody can tell him shit about his brothers. The day I found out I was pregnant his youngest brother came over and started an argument for no reason and got into a physical altercation with my SO at our home. I’m just tired of them always having to be included in our friend outings because they have zero class and are rude to people they don’t know for no reason at all. Sucks these are the uncles my son will have.