Why do guys do this??

I can't seem to know if this guy likes me or not. We used to lock eyes and sometimes still do. And he sometimes talks to me when its just him & me. A few times he called my name when iv been in front, so its good that he's making conversation. But the thing is i know he talks to other girls as there in similar lessons and all we do is have small convo or look at eachother sometimes. The other day he was waiting outside our lesson and i came and he looked and gave a faint smile and i dod it back, but then everytime this girl walks past who he talks to he always trys to trip her up even though im there. I know he's just friends with them but sometimes i get the sign that he likes me, as iv caught him looking at me then looking away, and i find him attractive aswell. Could he just be shy and shall i just wait and see?.