G.B.
Don't overreact! Ignore it or say you didn't get what he said the way he said it. Be very nonchalant about it. It will pass faster if you don't give him negative or positive attention for it. He's at the age for trying out new things. My grandson (5) sometimes won't answer unless you address him as Spiderman or Peter Parker (S'man's real name, I guess). No big deal. The less you make of it, the better. It's not naughty, just experimental.