Does he hate me?????

There's this guy in my english cl who flirts with absolutely every girl except for me. I have know idea why, I've never done anything to him. Whenever i talk to him he looks really worried or nervous also he sometimes even looks away even more nervously. Sometimes I notice him looking at me from the other side of the cl i turn to look at him and he smiles at me so i smile back. It's strange how he's really nervous and then normal, btw i think he has a crush on my best friend but he flirts with loads of girls so i'm no sure. do I intimidate him? does he hate me? does he like me? I'm confused :S Please help me!!!