Me him and his best friend against the world

I was at my boyfriend house from 12 in the afternoon- 6 pm. During that time around 3 pm his best friend that is female came over. He know that I don't like her because she lies on me to break us up. So he invited her upstairs while I was upstairs and told me not to cause trouble. I don't cause trouble I try to be nice and everything. I left before her because I have a  curfew she's STILL at his house and it's 11pm. She's all over his snap ( he never even post me once ), they lay down in the bed and cuddle together ( yes I do want to choke them both ). He didn't even text me back no goodnight text didn't even see if I got home. I feel like I should dump him soon. He's a good bf to me but when it comes to her, it's EVERYTHING for her.  Tomorrow I'm not talking to him so he could feel how it is