Ma and Pa are sitting out on the front porch one day.
"You know what? Junior's 21. It's time we taught him about sex. Junior, get out here!". Junior runs out. 'Junior, I think it's time to teach you about sex."
"Sex," says Junior. "What's sex?"
"Well," Pa says. "Take off your clothes, Ma."
So Ma takes off her clothes. "You see that hole in Ma? Watch this."
Pa starts doing it right there on the porch. A little while goes by and Junior's younger brother, Bubba comes out on the porch and asks what's going on.
"Ma and Pa are teaching me about sex."
"Sex? What's sex?"
"See that hole in Pa? Watch this!"