Peanut: Hey, Mom, in class today we were talking about cow udders.
Peanut: I dunno. We just were.
Me: Were you learning about cows?
Me: Was your teacher talking about cows?
Peanut: No. Everybody was just talking about cow udders.
Me: Ok. Cows have udders. That's where we get milk.
Peanut, giggling: We drink milk from cow wieners.
Me: Udders are not wieners.
Peanut: What are they, then?
Me: Boobs. We get milk from cow boobs.
Peanut: We drink milk from cow boobs.
Me: Furthermore, only girl cows have udders and only boy cows have wieners. Just like people.
Peanut, silent and thoughtful for a minute, then: Mom, how big is a cow wiener?