Girl is mean to me because she likes my boyfriend?

I started at a new school a few months ago. I started talking to people and made friends and one of the guys asked me out so we’ve been dating for a few weeks now. There are a few girls who act really weird towards me. They make it very obvious that they don’t like me and one of my friends even told me that they don’t like me. When I asked him why he said it’s because the one girl really likes my boyfriend and thought he was going to ask her out before I moved there so she feels like I “stole” him. She constantly tries to point out something negative about me when we’re around him together. What would you do about this?