Does he like me? and what should i do?

im jess and im a junior in high school, i have a mature crush on this guy in my calculus cl. he is the nicest guy you will ever meet, though kind of a follower. he is really shy and sometimes i don't know if he likes me or not, we went out with a group of friends a few times and he basically wasn't friends with the people there so maybe he likes me, however when we talk on aim he gives me short answers like he doesn't care and that really bugs me. his friends really don't like me and make fun of me in front of him, and my group of friends think he is stupid and i shouldn't even like him. do u think he likes me or he is just trying to lead me on? and if so should i tell him how i feel?