What should i do about this guy?

we have this spring ball coming up at our school and it's like the "big thing" one girl showed up in a limo last year e.e ( this is middle school-8th grade ) anyways, there's this super hot guy o3o we've been friends since the beginning of the year and he asks me to go to the spring ball with him, i said yes :] then expecting to be like his girlfriend now, i try to get his attention and he totally blows me off to hang out with the preps. this lasted all of last week. today he talked to me some because my friend told him that if he was just using me then she might have to do something about it. lol. at our "recess" type thing where we get to go talk to everyone and stuff, we were all in a group and he was standing beside me and talking and all and then preppy ( popular/supposedly the most beautiful girl in school ) Katy Moore walks by and he follows her. They are like walking all couple like and laughing. it just made me sick but then the rest of the day he was around me. then i get on myspace -.- blech myspace -.- and his mood is ktm <3 :) which i figured out is katherine's initials- katherine taylor moore. im so pissed right now. how could he use me? what should i do? when im at school he's all sweet but then i see things that infer that he is going out with this katy *****. i really hate katy, she gets everything she wants.