What the heck is he doing? He's messing it all up?

I met this guy about 5 days ago or so. We talked on the phone, exchanged ims etc. He was so smart and funny the first day i met him. We talked all night. and the second day we talked all night too! It was fun. Then he started not talking as much... literally his responses are two words long. I told him I don't think we should hang out cause it doesn't seem like youw ant to cause all you do now is respond in two word answers, all the same like oh wow. Oh ok. oh my. He's become so non chalant. UNLESS he talks about . (but thats just a lotta guys) help! Should I try to get out from hanging out with him? When i confronteda bout this he said he's sorry and he still wants to hang out. I replied with OK (because i was irritated, and felt like doing the same thing he does) and he still never replied back... What the heck is wrong with this kid?