Can sand break? and other impossible 4-year-old questions

In the car today, Hy was doing his usual--barraging me with random questions about the world around us--when suddenly the conversation turned.

Hy: "how do the babies get in your tummy?"

Me: (where in the world did that come from?) "they grow in my tummy"

Hy: "no, but how do they get in there?"

Me: (weighing my options...) "after a mommy and a daddy get married in the temple they decide to have babies come to their family"

Hy: (exasperated) "no, how does the baby get in?"

Me: (hmmm...) "the daddy helps the mommy get the baby in her tummy then the baby grows bigger and bigger until mommy goes to the hospital and the doctor helps the baby come out."

Hy: "how does the baby come out?"

Me: "the doctor helps it come out"

Hy: "but, where does it come out?"

Me: "from my tummy"

Hy: (after thinking for a minute)"but your tummy doesn't have any cracks in it...where does it come out?

Me: (after thinking for a minute) "mommy's have a special place where babies come out"

Hy: "only mommy's have it?"

Me: "yes"

Hy: (long pause) "I want to see it."

Me: "ummmmmmmmmmmmmmm"

Hy: "next time you are in the hospital I want to come and see where the baby comes out"

Me: "Hmm. That might be interesting...actually when your wife is going to have a baby and you are big like Daddy, then you can go to the hospital and see where the baby comes out."

Hy: (thinking) "alright"