Why do we playfully tease one another?

Me and a guy I’m getting to know (to build our friendship first) have conversations in person but they’re always playful teasing..
for example:

Him: you can’t just play tennis all day
her: yeah I can, and I will
him: we’ll I’ll just bin your rackets
her: omg noooooooo! We’ll football is boring so (he loves football)
him: we’re gonna have an issue you and I
her: excuse you! I haven’t played football so..
him: guess that would be my fault?
her: yeah it would be actually
him: oh alright then hahaha

do you think this happens in nearly every conversation because there might be some romantic interest there?
Why do we playfully tease one another?
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