In his 18 years on earth, Sam Jackson had always gotten along pretty well with his twin sister Jill. They had a simple rule between them that had always helped to keep the peace — "Paybacks are Hell". The idea was if one of them did something wrong to the other, the payback would always surpass the original damage. So if Sam accidentally broke Jill's sunglasses, the "Paybacks are Hell" axiom would mean he would have to buy her two new pair. While this simple arrangement had always worked to avoid conflict, it also ended up leading to a very unexpected event.
It was springtime, and their parents were out of town for a few weeks, leaving the two of them on their own. They were both finishing up their senior year of high school, so you might think it would be a pretty good time to have your parents leave for a few weeks. Most high school seniors would have a two week beer and sex bash if their parents were out of town, but Sam and Jill were not that typical. In truth, they were both kind of nerdy. They looked and dressed pretty plain, didn't have a lot of friends, and neither had done much dating. So most of what they were doing with their parents out of town was pretty much what they did when their parents were in town.
One exception was that with their parent's gone, they were both taking advantage of using their master bath, which was much nicer than the bathroom they shared. It was a big fancy marble bathroom with a spacious tiled shower and a jacuzzi tub. The bath was only accessible from the master bedroom, and didn't have a door. Sam and Jill would take turns using the fancy bath, it was generally easy to tell if someone else was in there.
But as fate would have it, on an early Friday afternoon Sam decided to take a shower at the same time that Jill was getting out of the tub, and when he waltzed into the bathroom, there was his sister, standing stark naked in front of the tub. Even though it was his sister, his first response was to thoroughly check her out, which he was able to do because she didn't see him walk in initially. What he saw surprised him. His sister, generally covered in non flattering clothes, looked pretty smoking hot without any. She had shapely breasts and a toned body, with great curves and perfect legs. He was taking all this in instead of backing out of the bathroom, which would have been wiser.
"What the hell are you doing?" screamed Jill, grabbing for a towel and covering up.
Sam was back to reality in a hurry, stammering some kind of excuse as he turned and walked out of the bathroom. He kept walking back toward his room as Jill continued to yell something about privacy, but his mind was still frozen on the gorgeous image in front of the tub. He felt bad that he had barged in on her like that, but he was stunned and intrigued at how hot his sister looked naked.
It was a few hours later before he would see her again to apologize. He was in the kitchen making some cereal for dinner when Jill walked in, wearing a robe and glaring at him.
He couldn't help but grin. "Hey I'm sorry sis, I didn't know you were in there," he said. "It was an honest mistake."
She was still mad. "I didn't even hear you creep in," she said. "How long were you there?"
"I wasn't creeping, I was just coming to take a shower," he replied. "And I really didn't see anything, I mean, it was just a quick glance."
"Really, you didn't see anything?" she said hopefully.
"Just a quick glance," he said. Then after a moment, "But damn you got a hot body."
She threw an apple at him that just missed his head, but she also blushed and gave a half grin. "You're a total creeper," she said. "Sneaking up on your naked sister like that."
Sam laughed again. "Hey I said I was sorry."
"Not good enough," said Jill. "You know the rule, paybacks are hell."
Sam groaned. Jill was pretty good at coming up with brutal paybacks. He was expecting to have to clean up her room, or do her laundry, or do the dishes. But his expectations were wrong.
"You saw me naked, so I get to see you naked," she said flatly.
Now it was Sam's turn to blush. And also to choke on his cereal. "What?"
"It's only fair, you saw me and paybacks are hell, so now I get to see you," she said, even more resolutely than before.
While the initial thought in Sam's mind was that there was no way he was going to get naked in front of his sister, another train of thought started to filter in, and thinking about the idea of being naked in front of a girl, even if it was his own sister, was starting to sound kind of...hot. He didn't have a lot of luck or experience with girls, at least this was something.
"So you actually want me to let you see me naked?" he said.
Now Jill had actually expected Sam to strongly reject the idea immediately, so suddenly she was having some second thoughts about the request. But she had opened the door and didn't want to be the one to back down.
"Seems only fair," she said.
Sam's initial shock and reluctance had now been fully replaced by the notion that being naked in front of a girl, even a girl who was your sister, had a certain excitement to it. "Ok," he said.
Jill blinked. "Ok what?"
"Yes, ok I will let you see me naked as payback," Sam said.
"Oh, well, ok then," said Jill, trying to not act shocked. In the back of her mind she was wondering if Sam was really serious or pulling her leg.
"So where do you want your payback?" Sam asked.
Jill hesitated, wondering if this was really happening. "Well, uh, I suppose we should return to the scene of the original, uh, crime," she managed to stammer out.
Sam was surprised that she was continuing to go along, but he wasn't about to stop. "Let's do it now," he said.