I hate my boyfriends best friend

Ok so I’m not gonna say my age or anyone’s real names but basically I’ve been dating my boyfriend for a little bit and I love him and he loves me I think but his best friend is INSUFFERABLE to be around he’s in my boyfriend and I’s class. I was cool with his best friend for some time it’s cool whatever but recently he’s been really touchy with my boyfriend and like the other day his best friend let’s call him Bryan was sitting in a chair and was leaning back my boyfriend was standing behind the chair holding it and his best friend loudly shouted “oh my god it’s like 12 inches!” I looked over gave them a weird look then I went back to reading. And his best friend is also just really really really mean to me he’s called me the f slur, fat, gay, ugly, stupid and dumb i also have to clarify that the only people that know me and my boyfriend are dating are 3 of my friends and I don’t know if he told anyone. He also knows I don’t like his friends at all but it’s fine I know he loves me and all I just wish his friends didn’t treat me and him like absolute shit Friday his best friend gave him a nosebleed on “accident” and his best friend also gets him in SO MUCH trouble So what do I do about this cause don’t wanna be toxic by telling him he has to stop being friends with them because he obviously won’t but that’s all