Baby Bears

Driving down the street this afternoon on our way to get a gift for a birthday party:

Z - Where do baby bears come from?
Mom - They come from the bear mothers, just like baby people come from their mothers.
Z - Oh, so they come out of their tummies.
Mom - Yeah...
Z - So they bite open their tummies?
Mom - No...
Z - Do they find a sharp stick and stick it in them and then the baby can come out of that hole.
Mom - Uuuhh, no. Honey...
W - No they don't come out their bellies, they come out down in between their bottoms and their privates.
Z - starts to giggle
W - No it's NOT funny, it's for real, right mom? There's a hole there, where the baby comes out.
Mom - That's right. (Curious about where this conversation will end up if she stays out of it.)
W - Mom, how does the baby not fall out?
Mom - Uuuuh... (driving west into the 6 pm setting sun, squinting, in stop and go traffic on a Friday afternoon while formulating a simple yet informative response on the reproductive genitalia of women for her 10 and 6 year old boys in the backseat...) well, it's just not open... it's closed like your butt hole.
W & Z - laughing (because mom said the word 'butt hole')
Mom - groan... pulls into parking spot at Wal-Mart. Alright, boys, what are we buying for your friend A? We'll have to hurry so we can get you to the party on time.
Boys - Start talking about which Star Wars action figures are cooler.