Does he like me?? What's my next move?

Okay, So, There`s this guy in my Social Studies cl. He's constantly looking at me, Stealing my pens/Pencils (But quickly giving them back) And flirting like crazy. My friend Sammy* says that he ISN'T a man , But i'm not exactly sure why he'd like me. My self esteem is pretty low right now, Unfortunately. I really like him, and with all this flirting he's doing, I'm pretty sure he likes me too, But not completely positive. I always catch him staring and he was showing my table of friends to his friend at lunch the other day. I tI really like him, but does he like me back, Or is he naturally flirty?\: Oh , And what should be my next move? Keep it simple and flirty or kick it up a notch? Talk to him more or what?.