He seems like he wants more than friendship...but why??????

My good guy friend had a breakup from a long term relationship a month ago. He was always flirty w/ me, but never crossed the line. We used to chat for hours, study together, he teased me, it was great. The month following his breakup, we chatted a lot (4hr+) and we grew very close. When I went back to cles, he doesn't even say hi to me, but blushes and kept staring at me. I get home, and he texts me tons w/ silly hw questions. Then again, he blushes and seldom talks to me in cl. When I texted him the next day, he doesn't answer my question, but texts silly stuff and then calls and talks to me. Even though I really like him, I can't help but think he is on the rebound. Why the sudden interest in me? I talked to him just now, and he tells me his whole day, ending w/ "now that I'm single, I can hang out. I hate my life...JK". Should I just back out for a while, so I don't get hurt? Or is he genuinly starting to like me?