It was the summer of their eighteenth year, Billy Bob and his twin sister Mary Lou had reached adulthood. Living in the hills of Kentucky with their ma and pa, they lead a somewhat sheltered life. There was no running water or electricity in the 3 bedroom house perched in the hills. As austere as it may seem, these were normal conditions for the time and the area. The local kids attended a one room school house and they were the oldest amongst the children who attended. Without having anyone else in the age group, it made it difficult to share ideas and learn stuff from the "kid on the corner".
One day of their birthday, ma made for them a hardy breakfast. Since this was a special day, both were excused from chores. Ma told them, that after dinner tonight, she and Pa had a special birthday present for them. After eating, the kids put their dishes in a tub and headed out to the local swimming hole.
"Whadda think they got us Mary?" Billy asked.
"Not fer sure, Billy." She responded.
Both of them swam in the watering hole, wearing the usual shorts and shirts. Billy had noticed how his sis was looking. Mary Lou was built like her mom. She stood about 5' 2" tall weighing about 105 pounds. She carried a 32 chest and he could see her large nipples through the wet shirt. Billy was like his father, standing 5'10' tall weighing a180 pounds. He was clueless as to enormity of his cock. He had no others his age to compare against.
After spending the day at the watering hole, the kids returned home for dinner.
"Now I want both of you youngins to wash up before supper." Scolded Ma.
Both of them cleaned up, put on clean clothes and headed into the kitchen. Ma had made a dinner of fried chicken, mashed potatoes, corn bread and other fixings. The family ate their dinner and after about 30 mins, the plates were eaten clean. The kids put their dirty dishes in the tub and went into the small living room. A few moments later, Ma and Pa walked in carry a birthday cake, singing happy birthday. The two smiled and began to sing along. Ma cut a slice for everyone.
When the cake was eaten, Ma looked at the kids and told them "For your special day, being adults now, your Pa and I thought it'd be best to teach and tell you about sex."
The kids had a somewhat perplexed look on their face. Mary Lou asked Ma "What is sex?"
"See what I mean. You two have no clue about what sex is, how babies are made and how to do it." Ma Responded.
Mary Lou responded "Is that like fornicating?"
Ma replied. "Fornicating is for sinful folks, whores and hussies. I'm talking bout when you're married. Sex is for married folks like Pa and me."
Pa added in. "Kids, fornicating is the work of the devil and you'll burn in hell for it. Any other questions?"
Both kids shook their heads no. Ma started the lecture and stood up from her chair. "Now I'm gunna splain the parts of the women and your Pa will do the same for the men. Ma began to unbutton her shirt and pulled it off. Standing proud, she bared her tits. Holding one in one hand, she pointed to the nipple and said. "When women are preggers and after having babies, their teets get bigger and make milk for the baby. The baby sucks the milk from the mommies' teet. Anyone got questions?" Both kids sat silently. Billy looked at how nice his Ma's tits looked, full, firm and with large nipples.