Sounds like you are sometimes the object of the Mean Girls phenomenon. I have been there. They are telling you that you are not accepted, not one of them, for some reason. Maybe they fear you are a lesbian, or more wealthy, or more independent than they are. I dont think there is a solution for it - they need someone to feel superior to, for someone to be "out." Try finding a better group of losers to hang out with, as the country song goes!