Why do guys do this ?? Please give me some advice !?

I met this guy a little over a week ago. We met at the bar and he got my # from someone and called me while we were at the bar. He even called me after we left the bar. He said he'd call me 'later'. The next few days rolled around and I didn't get a phone call. This is not normal, guys always call me back. I ended up texting him a few days later saying hello and he replied. I was at the bar the other night and he was calling me because he was there. But he didn't come up to me ?? Anyways I ended up hanging out with him all night and we kissed. Once again he said he'd call me later. It's been 3 days and he hasn't called! Is homeboy into me?? I won't call him because I don't like to seem desperate. My friends think he's just playing hard to get. Do you think this is true? Do you think maybe he's just shy? Or maybe he only likes me when he's drinking?? What's his deal?