Am i being used, why is he doing this?

This kid was flirting with me, puttin his arm around me and stuff. My friends kept asking if i liked him and if we were going out, i kept on saying no. then later he went and talked **** about me, calling me ugly and stuff. i was really hurt by this. But, then me, him, and a couple friends went to the movies together. he walked away from the group during the movie and was like "Reyna, follow me" i didn't really want to follow him. i mean, i kinda liked him, until he said all of those mean things about me. but, i stupidly did follow him. we went to the other side of the movie theatre. he put his arm around me, and started stroking my elbow (kinda weird but it felt nice) and he kept putting his head real close to mine, and staring in to my eyes. But of course, our friends came over and ruined it haha. they were like, "aww how cute, you two should go out!" and i was like "shutup" and then the guy was like "you know, i don't like you like that" that hurt me even more. But then yesterday, he walked me to cl, and he said he didn't care if he would be late to his other cl. wtf?? okay he doesn't like me, fine, but why does he keep on flirting with me? he's not gonna get some from me, i mean, everybody knows i'm not a , i'm like, really shy and quiet and stuff. and i have not done ANYTHING inappropriate with a guy. how do i tell him to back off?