Monster-In-Law Strikes AGAIN.

Okay so last night my SO and I stopped by his parents to give his mom $ for ordering my bridesmaid dress for his sisters wedsing. 1. I said I'd buy it. 2. She insisted and said it'll be my birthday present for the 15th. Okay well I thanked her a lot and said she didn't have to. (She hates me and I know she knows I hate her).  Anyways, we were all at the table, her, his dad and sister and her fiancé. We were discussing people eating their placenta (my brothers ex did it) and I tried explaining to them the process and ways you can consume it. Well the whole time his mom was making rude remarks and josh pissing me off making me sound stupid. At the end, I got up, threw out my food and washed my dish as my BF came up and said let's go ok? I said fine. I'm petting the dogs and she says, "I'm sorry for making you mad Nicole" while laughing and I said, "ah it's ok I'm used to it ". Well she then replies, "fuck you you fuckin bitch!" And I turned around and said thanks and goodnight. Why the fuck should I have to put up with her bullshit? I never stick up for myself with her and I finally do and idk I feel bad but not really. I hate his family so much. His mom walks around like her shit don't stink and how she can buy anything she wants whenever. I told my boyfriend I'm done seeing them and want nothing to do with them. His reply is, "they spent 10k$ on us with this house Nicole why can't you just ignore it" I said "uh because you can unload your pockets for me and treat me like shit, I still won't fucking like you".