I REALLY like this boy, but he has a girl friend?

I'd like to know why teenagers get engaged, but whatever. It doesn't matter, and no you are not "falling for him." It takes a considerable amount of time spent with an individual on a 1-on-1 basis to actually feel anything remotely like love. You are infatuated with him. It sucks he's in a bad relationship, but its not your place to make him realize that. I say do not approach him, do not speak to him, avoid him at all costs. You shouldn't compete for anyone, or put yourself in a situation of trying to "steal" him from another.