I asked this already ...but why would a dude do this?

Most likely the guy likes you. Guys usually go with the teasing method to flirt with girls at least for a while, because it's easy and for most girls it works. He probably keeps bringing the things up because he thinks you thought it was funny too or he gets a funny reaction from it. It seems like to me that he might be taking it a little over the top though, but based on the way he hangs around you and the other details I'd say he likes you.