What does it mean when a guy makes eye contact with a girl more than once?

this guy, who's 2 years older makes eye contact with me occasionally in the hallways (im too scared to look sometimes tho, in case he thinks I like him or something) I mean he's hot and all but I don't want him to think anything because he might just be looking to see if I'm looking at him... Anyway, this one time he was walking out of the school library and I was walking in the opposite direction. He looks at me, glances away quickly (like a second) then looks back at me and we make eye contact again (then he just looks away quickly). Like what could that mean? if anything at all... Does he think I'm a creep? Do guys make eye contact at a girl who they think is ugly or creepy?