How can I tell if he's into me?

He sometimes looks at me with the most intense look. He's shy about it but he's really eager for us to hang out. Twice today he hinted about hanging out in our rooms together. I can't really tell if he's bi or gay. He never talks about women, which would seem odd for a straight guy but maybe it's because he's mature. Don't straight guys talk about women and sex, at least once and a while?