It seems to me that he definitely has an interest.
Maybe he's just gauging your response to the hand kiss before laying it on the line. Was he being silly? Just trying to be funny?
Did he do it in a dramatic way like with a lot of bravado? How did you respond? He's usually kind of a silly guy. But he seemed sort of mellow at that moment.
I just smiled and said, "I'll see you soon, I'm sure. If he does it again, and you're into this guy.