I play in concert band at school, and there is this one girl that I've known for maybe two years that is a narcissist. She's vain, selfish, egotistic... I've been putting up with her for years. She plays the same instrument as I do, and if you've ever participated in some sort musical activity, you'd know it's important to keep together and work as a team. Not the case. She doesn't care what anyone else does, All she can do is tell everyone how superior she is compared to everyone else. I've tried to tell her, believe me.

Today I was in a particularly bad mood, and she was telling the conductor that this piece of a song was difficult for us. I couldn't resist, I told her to speak for herself, everyone else knows that piece quite well (she never even attempts to practice because she is apparently automatically better without it). She also dances 5 hours a day, and I told her that if she couldn't keep up, she shouldn't be here. At the end of practice she ask me why I hated her so much, and she started a heated argument on how I am trying to pull her down and that I am jealous, she even admit ed that she was selfish, competitive and egotistic. She then ran off to tell another friend of mine that I think she is a female dog (which she is I won't lie), but I've never hated her, she just makes me so angry sometimes.

What should I do in this situation?

Much appreciated,
Ali