I find when I'm engaging in banter there isn't an issue being clever or fun.

But when asked a question out of the blue, I automatically give a cold, hard, factual answer.

Recent example:

I was studying for a significant exam with a cute girl, focused on being prepared. My mind is in work mode.

Suddenly she asks "do you think vampires are real?" to which I gave a cold "no" and started to explain why not.

I then caught myself and started teasing her about how if she was a vampire she would never see the sun or the beach, and kept the tone silly.

So other then just practice, is there a way you taught yourself to respond by default in a fun, playful manner?