What does he want from me?

I'm 20, he's 35. He's a gorgeous guy. Got a good career. He told me he's content being single, but that he wants to meet his soulmate. We've been flirting alot lately, and we even have pet names for each other. He's always trying to impress me with his accomplishments...I don't know why, maybe because I'm still in college and he's a P.E./health teacher and I'm a science major? Hmm. He really hinted at me coming and seeing him alot a couple weeks ago, but it just didn't work out. He was gonna come see me a few weeks ago but I had to cancel on him. We usually text each other good night almost every night but now it seems things are cooling down quite a bit. He's always telling me how beautiful I am, and how I am perfect the way I am. He said once that when I make him laugh he is a happy man inside. I thought that was sweet. He has such a way with making me feel like the only woman in the world. But I can't help but wonder what he wants from me? Just sex, relationship, friendship (a flirty one of course), or like brother/sister kind of thing? I'm sooo confused!