Confusing guy!? Teases me whenever he sees me but never talks to me

I don't know whether this guy in my class likes me. He teases me with random guys, calls me names, he notices everything I say or do and often makes fun of it, he keeps looking at me sometimes and when I see him looking at me, he says something stupid or we both end up laughing. He also gives me these weird deep stares. Remember that he's 17.

But at the same time, he doesn't talk much when we're alone. If I am sitting somewhere, he'd just walk up to me and say nothing. just pick up my pencil and say that he's not going to give it back. If he has nothing to say then he'd just ask for my water bottle. But when I try to start a conversation. he just seems awkward. like he doesn't maintain eye contact and looks down or says something stupid or just keeps looking at me blankly without replying.

But at the same time, he has this girl friend to whom he talks openly. They also have the same group of friends so they hang out often. They also walk home together and also he keeps talking to her during class. But he doesn't flirt with her or tease her. but she's a really good friend to him. And I get very jealous seeing them together.

What's going on here? Why doesn't this guy talk properly with me as he does with her? Does he even like me?