Help!

So my bestfriend is a guy. And he’s always been flirty but never this much. Whenever I get mad I always tell him “go fuck yourself” or “fuck you” and he always just laughed. Now when I say it he either says “I’d rather you do it” or “when”. And he’s been using more emojis lately too. Like yesterday he put “😘😊😘😊” Like what does that even mean? What should I do? I can’t confront it, cuz if he’s doing it as a joke that would make things more awkward. Help!!!!