Please help. guys in there late teens. thanks in advance?

Ok so there is this guy i really like and we were chatting alot and he would really flirt online. Today when i met him at the university (I wanted to meet with a teacher and he was meeting with one next door) i got kind of shy and just said hi he came and stood by me and was talking about how he felt relieved he finished his exams today(i finished june 4 wayy before) and just couldnt find a way to celebrate anyways i was texting a friend and ddnt really get into the conversation though i did ask him a couple of questions to keep the conversation going. anyways he went in to meet the teacher and when he went out he just walked away!!!!!!!!!!!!! why wouldnt he at least say goodbye? does it seem like he likes me? i seem to start the online convos recently and he is nowhere near asking me out!