What does this mean?? help!!?

Before you read i just wanted to say I'm a girl even though. My name doesn't seem like it...yes ryan is a girls name too. So there's this guy that I have 3 classes with(1 for PE and 2 for band). I know him but we never talk. Sometimes in PE (there are 3 PE classes in our period so were not in the same class but we have the period together) I've seen him staring at me. I don't see him looking during our other two classes that much but every once and a while I do. Btw hes a senior and im a freshman but i have a friend that knows him well and hes not the type to use girls for sex. Why does he do that?? He never really does anything to make me think he likes me so I doubt that he does. What does this mean?? thanks:)