An extremely odd situation...what kind of relationship do we have???

We've been friends for 2 years. I've liked him for a yr. We've just kept growing closer and closer. Last year, we exchanged aim id's and grew very close. Now, we talk on the phone every few days, text a LOT, and chat online for 4+ hours every other night. We have all the same cles and all the same friends. But w/ mutual friends around, we act as though we barely know each other. When they're not around, he is so outgoing and extremely loud around me haha. Online he tells me personal things, and asks me personal things as well. We know SO much about each other. Weird thing is, we've never really said plainly that we're friends, or even what we are, if we're more. He had a long term gf until 3 months ago. He doesnt talk to other girls @ school, but has a few friends who are girls. Its hard to tell, as I feel when he looks at me, he likes me more than a friend. My friends suggest the same, as they say he acts nervous/stares at me, but nobody can tell. Suggestions?