I like this guy but this year were not in the same class. He's in the other class were thers this other girl who likes him. My friend in the other class says that she is all over him. But I really like him iamd a don't want to give up help

There will always be "other" girls everywhere,

If he will not stay true to you, he won't anyway

You can't make someone like you, especially if you two are hardly ever around each other. Make friends with lots of guys. Friendship is the best foundation for love.

He isn't even your boyfriend, so you shouldn't be worrying about other girls. If you're this jealous over him being in another class with OTHER girls, imagine how you would be in a relationship. From how you posted, it seems as though he doesn't even know that you like him. Why get protective over a guy that isn't even yours? If you like him so much, tell him and ask him if he thinks the same. It's ridiculous to fret and stew other girls liking him, or him being around other girls, after all, he has complete freedom to do what he wants.