How can you tell if your guy friend likes you..?

Well recently i moved to delhi, and on my first day of school i had sat by a cute guy named Rafael Ramirez he seemed cool and i had my eye on his friend, but it has been months and i have been flirting with his friend and i got closer to him, but he has a girlfriend now and i moved on.. and last week we had different seating charts.. and funny i sit by Rafael in BOTH of my cles. And we are also close now.. and i think i like him, we flick each other a lot in both of our cles. is this a sign of him liking me back? or is this a sign of him being a cool guy friend? can you give me more signs that a guy friend would show to a friend as a girl that he likes her? HELP ME!!