What is Wrong with this Story?

My friend has this amazing cousin I've liked for a long time now, and she keeps saying that he likes me. Whenever I see him, it seems like he's flirting with me and then I get all happy. But then he starts talking about all the girls that he's dated and all the stuff that he did with them, and I'm like, "Why are you telling me this?"

Whenever I say that, he goes more into detail. I know he jumps from girl to girl quite a bit. But whenever I talk about a guy that I like, he changes the subject.

He knows that I like him, so why does he try to make me mad? I asked my friend and she just said that he does like me and that he is trying to impress me. I still am pretty much in love with him. I see his name everywhere I look, but I don't know how this is ever going to work out.