Why do guys tease girls in a mean playful way?

mean everyone does this from time to time I even do this to. But this guy I don't know like he playfully teases me and stuff, but it always like back hand. Like we work together, and he decided to sweep my floors lol and I was like aw you're so nice like nice teasing on my end.. cause he has no need to do that and it not my job to do it either, but he responds with a "well god knows you won't do it" (it wasn't even dirty. and I was saying you're going to make me look bad and he responds with I make everyone look bad. And if he is waiting for a customer I once said who you waiting for until I clued in.. and he just says "not you." and laughs But he punches me playfully and pretends to kick my stuff.. I mean I know it just sarcastic but Jesus it always like a back hand thing or something. He's friendly it not like he's pissy or anything. Also, if he is in my way he will be like if i was nice i would move stupid stuff like that.