I'm Guessing Cocoa Puffs

David, coming into our room on a lazy Saturday morning: Can I have my breakfast?

Me: Yes. Are Charlie and Sarah downstairs?

David: Yes.

Me: Then ask one of them to pour your cereal for you.

David, trotting off: OK.

Me: What are you going to have?

David: Oooh, I'm not telling. You'll have to smell my breath.