[PSY]

These girls don't expect you to stand up for yourself. They believe they can walk all over you. Prove them wrong. Since they're so "nice" when they're alone with you, why not confront them then? Say that you really enjoy your friendship with them, but the constant ridiculing is bothering you. Having similar interests as your friends, and wanting to participate in the same activities as your friends (whether it's going to the same concert or buying a pair of shoes) is something your friends ought to be flattered about. "Copying" is a sign of admiration. (Okay, let's face it... no matter how you phrase it, these girls are still going to believe you're copying them... so rather than denying it, why not spin it in a way that makes "copying" seem like a good thing?)

If these girls are going to keep treating you like trash, then stop hanging out with them. You have other friends who don't treat you this way... why not spend more time around them and get to know them better? Your friendships will eventually become stronger, if you're willing to put time and effort into them. If you put even 10% of the time and effort into new friendships as you do into these so-called "friendships" with these so-called "friends", then I guarantee you'll be MUCH happier with your social life. And if these so-called "friends" talk about you behind your back and try to manipulate people... so what? "The people who matter don't mind, and the people who mind don't matter." Basically, the people who would believe rumors about you aren't worth associating with in the first place, as they are fickle and small-minded people. The ones who take the time to get to know you, however, won't buy into those rumors.