"Redneck Sex Ed" joke

One day Ma and pa were sitting on the porch, when Pa said to Ma junior's 21 years old now" It's about time we teach him about sex".
Ma said "ya know pa your right".
So pa said to junior "hey junior come on out to the porch for a second".
so junior came on out to the porch, Junior says "ya pa whatcha want".
Pa said "junior it's about time we teach you about sex".
Junior said "sex what's sex".
Pa turned to ma and told her to take off her clothes, so ma does, and she does a spread eagle right there on the porch.
Pa says to junior "see that hole in ma? watch this". So pa starts going at it with ma.
In the mean time juniors brother comes out to the porch, he's 18 and says, "Junior what's ma and pa doing".
Junior says "their teaching me about sex".
Junior's brother says "sex what's sex".
Junior says "see that hole in pa watch this".Red