Boy advice!!!

Okay there's a boy I've liked about 2 years. I've always thought that maybe he likes me back. There are times when he'll sneak up behind me and scare me (always terrifies me), a couple days ago in our band class he sat next to me, and after I played he like touched my shoulder and was like play louder, I was gonna say like, wait say that again? But then I see him doing similar things to other girls. Like a friend of mine. She's kinda bitchy to me sometimes, so Idk if id call her a friend. But he's always like, (if I try to complain about her) What??? She's SO nice, she's Canadian!!! And he's always sneaking up behind her to scare her and sitting with her whenever we have a sub in class, and I just don't know what to do. I don't wanna ask him out cause we have an AMAZING friendship I know that if he doesn't like me back, it'll be SUPER AWKWARD. Any advice girls on what to do? I'm young and oblivious to like everything...