My son asks me, rather loudly:
"Mommy. Was I hatched from an egg?" (snickers from patrons sitting around us)
Me: "Ahhhh. No, you weren't."
Him: "How was I born?"
Me: "From Mommy's belly."
Him: "How, Mommy? How? How was I born?"
Me: "It's really not something we talk about at the dinner table at a restaurant."
His sister: "Don't worry. When you get married to a girl you'll find out then."
And that ends any apparent need for me to discuss the birds and the bees with my son, because his future wife will take care of it. Phew.