Does he keep staring at me b/c I look at him? We're in college?

long story short: met a guy my freshman year who lived in my friend's dorm. He's from the same state as me and we know similar people. Anyway, after talking to him my friend told me he said I was a cool girl. I didn't think much of it ,he's the jock popular type and I'm the quiet nerd (well now that I'm a senior I'm much hotter lol) so maybe that's it, but I notice him staring at me and looking away like ALL THE TIME in class at work etc. Last night at a frat party he saw me and said hi and gave me a side hug. He was with other girls tho, so I didn't really talk to him, but he did keep staring at me. What's up with that? If he liked me, wouldn't he ask me out?