A Conversation Gone Horribly Wrong

Scene: Our minivan, waiting for Sam as he ran into the store.  We were having a discussion about pets.

Me: Sambo, what kind of pet would you like to have?
Sambo: A dog.
Me: What kind of dog?
Sambo: A big, big, big, big, big, big, big dog!

(Sam returns to car)

Me: Sambo, tell Daddy what kind of pet you want (Sam also wants a big dog, so I want him to know he has an ally.  My intentions are good.)
Sambo: I want a big, fat dog!
Anne: Yeah, a big fat Daddy dog!

(Sam and I were dying with laughter in the front seat.  My well-intended prompting turned into a major insult.  Kids are so unpredictable.)