It seems that since the dawn of time neither the parents nor the children want to have this discussion. Leave it to the gym teachers. Which I remember from 9th grade when it was so late it was funny.
Ah, how about another topic no one wants to talk about. By the age of ten I am sure that any kid with access to a computer has seen more than enough prom to know where babies come from. Semen shot far into the air and then absorbed into a woman’s skin.