Could easily be because he wants to treat you special because your a friend. A lot of guys, keep in mind young guys, will say "hey babe whats up", "how you doing girl?" or other words that you would think belong in a relationship but it is merely because they are good friends with that individual and want to use different word around them. Or he could be interested, but you would not know that unless you ask him how he feels about you. I would not over analyze things guys say, sometimes they just want to say nice things.