Mixed signals from a guy...?

i've liked this guy since freshman year until our sopre year and i think he likes me too bec. he's kinda like flirting w/ me but then in the middle of the year i found out that he was courting another girl so i decided to forget about him. But now in our sopre year he doesn't even say hi in the hallways when we p each other,, he just stares at me gloomily and walks away but then his friends tease him about it then again in the middle of the school year i find out he's courting a senior. He's giving me mixed signals. What should i do? Is he just trying to make me jealous?