Why does he keep staring at me?

[Danny]

First things first, I'm going to address the elephant in the forum - you still like this guy and are hoping he likes you back.
Now, here's how to suss him out:
A) Find a plausible excuse to talk to him - get your foot in the door. From what you've told us, the best time is when you two are alone on the bus together. Ideas include: "my phone is flat, can I borrow yours to send a text?", drop a book or two over his seat so he picks it up for you. Be creative - you'll work something out when the situation arises.
B) Once you're in, try to find common ground to talk about (class, upcoming events, etc.)
C) Invite him on a group outing (perhaps with his and your female friends all together). He may be more comfortable in a group setting. I reckon the best choice would be the cinema - make sure you two are sitting together.
D) By then, you should have an idea if he likes you or not. Invite him to another event (even if it's just a trip to the shops or the beach or something) - just make sure it's only you two this time.

P.S. In step C) make sure you two are the only males in the group (he is unlikely to give any hint about his sexuality if he has a male friend there)