He tries to make me jealous after a fight..it's bothering me!?

Ok so theres this guy. He's white and I'm black.We didn't talk much. but we had became like friends. Not good friends. We have 2 cles together. but i sit next to him. I like him alot. but then one day he was in a bad mood and yelled at me, but i totally went off on him for doing that. I sent him a message on myspace cursing him out.So we don't tlak no more.And so after we came back form winterbreak he came up to me and said " O i gave the girl i like my pword to my myspace and she read your message". Anyways lately i always see him hugging the chick.Today at the pep rally i was sittin with my friends dancing and he was sittin behind us. And i everytime i looked up he was looking at me...but the girl was sitting in his lap! and he looked at me everytime i looked back. When I see him he's with her and he give her hugs. I don't like him anymore but this is bothering me! O yea the girl is in my dance cl and she's nice to me. she knows nothing about us two. Why is it botherig me?!!