Reverse psychology? Really?

Peanut: Mom, can I have another piece of Easter Candy?
Me: No.
Peanut, squealing and stomping: Why-y-y-y?
Me: You didn't eat your dinner, and you already had a piece.
Peanut: Moon had two pieces!
Me: Moon ate his dinner.
Peanut: Mom! Please, can I just have one more piece?
Me: I said no.
Peanut, whining even more: I want one more piece of candy. Please. It's not fair. I want another piece.
Me, at the end of my rope: Fine. You know what? Eat whatever you want. Eat all of your candy. Go ahead.
Peanut, stomping off to his room, without candy: Hmmph!

An hour later....
Peanut: Mom, can I have a cookie?
Me: I told you, eat whatever you want.
Peanut, exasperated: Fine! I'll just eat a carrot, then!