[He'll automatically assume it's 6 years old because he's dumb like that and that's tots the way you youngsters like to talk nowadays.]

Hey, you have quite a wild imagination for a 6 years old, kiddo! Kudos to your think pan. I'm not that smart or creative, so you're going to do great when you're around my age! So what's your story about?

[Well, he totally forgot about the water deal and he'll probably stop shouting for a while, so.]