Candice stared at the screen. In front of her, a perfect 3D rendering of herself floated in the Master PC window. As soon as she’d gotten home, Candice had quickly set the “sexuality” slider back to 30%.

She’d found some help files in the install directory and had been poring over them. Sometimes they explained an aspect of Master PC in a very straightforward manner. Other times, they were obtuse and circular in their descriptions. But she had learned a lot. The “Sexuality” slider went from 0% to 273%. She had, therefore, assumed that 100% was the normal baseline, and above that were those raging nymphos from the stories. But it wasn’t. It turned out 100% was the maximum level of sexuality a normal human body was capable of. Anyone over that number would literally die from sex. Above 100, they would generally start ignoring things like food and sleep. But by the 200s, an orgasm would short-circuit the brain in such a way that a person would be essentially catatonic.

Extreme caution must be taken, the help file noted, to harden the body and mind when setting the Master Sexuality slider this high.

Candice shuddered at the thought of what she could have done to herself. She resolved to start taking things slow. She began opening the profiles of as many other people as she could think of and comparing them. She discovered that normal human sexuality seemed to exist in a fairly tight range. There wasn’t enough data to do a really great analysis, but she suspected this was a typical bell curve. Most people seemed to hover in the 40s to 50s. She found a few people in the 60s (usually younger folks, and more likely than not to be men) and a few like herself in the 30s (more likely to be women or older folks). She only found one person she knew below the 30s, a girl she only knew in passing from college who identified as Asexual. Surprisingly, the highest she found was her neighbor in the apartment across the hall. Mildred was 83 years old and 68% sexual. You go girl, Candice thought.

After that she pulled up a few famous people. The first was a well-known actor from the Marvel movies. She could see his settings, but the controls were grayed out. She wondered if there was a geographical range, so she found a random person who lived in Japan and opened their profile. It worked. So someone — or something — was blocking out famous people? She found a list of billionaires and tried to load one of the less famous ones. A password prompt appeared. Huh. Even more protected. She decided against even trying anyone else. The Master PC Police would probably come after her if she even thought about messing with the President of the United States.

She wondered again who or what had created the program. Aliens? A wizard? A god? The God? There was no hint anywhere in the documentation.

Candice decided to go back to fixing herself. She had already undone the change to her sexuality. She began to undo her physical changes as well, but as soon as she did, she felt those extra 30 pounds immediately. It wasn’t pleasant. Ugh.

OK, maybe I won’t undo all the physical changes, she thought. She dropped herself back down 20 pounds and clicked Apply again. She was still ten pounds over where she was earlier in the day, but it was definitely a lot more comfortable. She decided to use this as an experiment. Would she be able to explain away the weight loss when someone inevitably asked? There was an entire section of Master PC called “Secondary Control Effects.” These were things like “Commanding Voice,” “Hypnotic Eyes” and “Pheromones.” They all seemed to be effects that didn’t change the subject, but allowed the subject to change other people. Here there was an option called Acceptance that the documentation seemed to indicate would cause others to not notice changes in the affected. You could turn someone blonde or give them giant boobs and suddenly everyone would just accept that as normal. Candice considered using that on herself to disguise her weight loss, but the documentation was unclear if it would affect herself. What if she turned it on and then accidentally turned herself into a sex-crazed maniac again? Would she accept that she had always been that way instead of changing herself back? She couldn’t risk it.

She did give herself the Command Voice, though. According to what she was reading, it could be used fairly well as a fallback to make people ignore changes, at least to an extent. Plus, she wanted to try it out. So often in the Master PC stories, the program was used to turn some smart, confident woman into a brainless sexbot. She liked the idea of using it for non-sexual stuff.

She considered upping her own intelligence. Maybe she could reason through this thing a bit better if she was smarter. But again, what if she messed it up? What if she turned herself into an emotionless logical machine? The Mental section was a maze of options and configurations: Puzzle-solving, Emotional Perception, Logic, Induction, Spatial Reasoning, Calculations. All of those and more were present and those often had multiple sub-sections. And there was basically no documentation for any of it. Clearly this wasn’t what most people were using Master PC for.

She needed someone else to experiment on. It needed to be someone other than herself, but someone she could keep an eye on. There was really only one option. She pulled up Richard.

She browsed around his personality and mental tab a bit. The Personality Indices were hard to follow. Here Master PC displayed an oddly shaped 3D model with different personality traits mapped out like “Empathy,” “Conscientiousness,” and “Leadership.” As she moved some scroll bars, it began to distort. She thought she’d made changes to him for a moment, before realizing it was just changing the view. More personality traits came onto the screen as others disappeared.

The Human Personality, someone had written in the documentation, is here represented in a seven-dimensional space flattened into a 3D model for easier viewing. It is recommended to simply use the Sexuality tab for most use-cases.

Well, that wasn’t helpful. She did notice that Richard’s self-confidence was low. She double-checked it against several other people to be sure. Candice had always suspected he had some deep self-doubt, this was just confirmation. She decided to fix that. If he became an insufferable prick, she could always turn it back down.

She began to dig into the Intelligence settings on his Mental tab. Comparing him to several other people, it seemed like Richard was already a little smarter than average. But not quite as smart as herself, Candice noted with some smugness.

Well, not for long. He was about to become the smarter of the pair. Candice turned up his Induction, Deduction, a few related values until they were a bit higher than her own. She’d watch him to make sure he didn’t turn into a Vulcan or something and, if the changes seemed safe, she’d apply them to herself after a few days.

She saw his avatar stand up on screen and realized he had made it home. They lived downtown, about halfway up an apartment high-rise. She watched him as his avatar mimed parking his bike and walking to the elevator.

She grabbed her laptop and moved to the couch, sitting against the wall so he wouldn’t be able to see the screen. A few minutes later the door opened.

“Hey, hon!” he called out. “Feeling any better?” Oops, she’d forgotten she was supposed to be sick.

“Yeah,” she lied. “Mostly. I was throwing up a lot this morning, but I’m mostly better now. I think it’s one of those 24-hour stomach bugs.”

“Oh yeah,” he said, “I had that last month. Do you think you’ll want food tonight?”

They continued chatting the rest of the evening. Candice watched him for any personality changes, ready to revert what she’d done at a moment’s notice. But no red flags surfaced. He wasn’t some insufferable overly-confident buffoon. He wasn’t a super-genius either. He didn’t even notice the weight loss! Admittedly, she was wearing her loose-fitting “fat” clothes, but still. Twenty pounds is a lot when you’re 5′3″! Richard had never been the most observant guy in the world, and the normalcy of it was kind of reassuring.

They ended up ordering Thai and watching Netflix. When they started the second episode, Richard put his arm around her and began gently rubbing her arm in a way that, after all these years together, she knew meant that he was interested in sex. Candice considered if this was anything to take note of. As far as Richard knew, she was still a little sick. Would he have tried that normally? Was this an indication of higher self-confidence? Or was she reading too much into it, and it was just that they hadn’t done it in nearly two weeks? It was hard to tell.

Sex. It was a subject she’d been trying to avoid thinking about all afternoon. The thought of Kevin fucking her in the changing room in the Abercrombie and Fitch flashed through her head again. The way she’d sucked his cock, the way he’d bent her over and fucked her senseless. She felt a deep sense of arousal thinking of it, as well as an equally deep sense of guilt over what she’d done. This whole thing with Master PC had started because she was worried about Richard straying, but she was the one who’d cheated. She hadn’t been in her right mind, but she knew it wasn’t an excuse. She’d sullied their marriage in a way that she knew Richard would never forgive if he found out, and she’d never really forgive herself for it either. She couldn’t undo it, she could only try to make amends. She swore to herself she’d use Master PC to make both their lives better, and to make their marriage stronger.

Maybe she should just lean into the sex tonight, she thought. Richard wanted it, and she owed it to him. Of course, no man was owed sex from a woman. That was a bedrock principle to Candice, and one that Richard agreed with. It was one of the reasons she loved the guy. But tonight, honestly, she did kind of owe him.

The problem was, she didn’t really want to. The thought of sex right now just wasn’t all that appealing. Only thinking back to the sex earlier in the day brought any sense of arousal.

“I’ll be right back,” Candice said.

Richard tried to hide his disappointment as she left his embrace and headed for the bathroom. She grabbed her laptop on the way and pulled her own profile back up. 80% sexuality had been far too high. But now she knew what most people’s numbers were. She turned herself and Richard up to 55%. Plenty of normal people were higher than that. Besides, she reasoned, even if something somehow went wrong, she’d managed to fix things before. She could do it again. She clicked Apply, closed the laptop, and headed back to the living room, snuggling back up with Richard.

This time, when he put his arm around her, Candice rested her hand on his lap and began making little circles with her thumb. It was the beginning of the little mating dance they’d developed over the years.

“I thought you were sick,” Richard said, smiling.

“Well, I’m feeling much better.”

He skipped a couple steps of foreplay and kissed her deeply. Candice melted into it. She’d only bumped Richard’s sexuality up a few percentage points, but her own increase had been much more significant. She responded with an unusual amount of enthusiasm, running her hands along his crotch, feeling his erection already swelling. The room seemed to crackle with sexual energy as their makeout session became more intense, like teenagers who were worried their parents would get home any minute.

Richard slid his hand under her shirt and she moaned as he began to play with her nipples. Candice’s nipples had always been very sensitive, but this was a whole new level. Only Kevin had made them feel this good before. She tried to banish the thought from her mind. Richard was her husband, Kevin was a one-time thing.

“Man, you really are feeling better,” Richard joked, as he ran his hand down her back, past her waistline, and grabbed her butt just the way she liked.

“Yeah,” Candice laughed. “God, I want it bad tonight, hun.”

“Mmmm, I can tell,” he said, as he pulled her shirt off.

“Woah!” he exclaimed.

“What?” Candice asked, suddenly gripped with panic. Did he somehow know about Master PC? Kevin? What was it?

“You’ve lost a ton of weight! How did I not notice?”

“Oh,” she replied. “Yeah. I’ve been working at it for a while.”

“Huh,” he said. “It’s funny how when someone is losing or gaining weight, you just don’t notice until one day you do.”

“Yeah,” Candice agreed. “Funny.” She decided to try something.

“I’ve been hitting the gym on my lunch break lately. YOU SHOULD GO TO THE GYM SOME TOO,” she said, putting the Command Voice into it. The sound that left her lips was uncanny. It was her voice, but it was also more. Underlying her natural tone, a subtle but powerful series of harmonic chords seemed to vibrate in the air around the words.

Richard blinked, as if he’d just been hit in the head with a rock. “Yeah,” he agreed after a second. “I really should.”

“Anyway, where were we?” asked Candice, grinning.

“Right,” he said, leaning in.

They went back to making out, but not for long. Richard was eager, and Candice equally so. When Richard’s hand slid into her pants, Candice was surprised at how easily he was able to slip his fingers in, and how good it felt as they worked her pussy. He pulled her pants down and lowered his face to begin licking her clit, as he always did. Candice was capable of vaginal orgasms, but only after a “warm up” clitoral one. It was the one thing that, therefore, never varied in their lovemaking.

“No,” she said. “You don’t need to tonight.” She guided his head back up to hers and bit his ear playfully. She opened her legs slightly, letting him slide between them, and began tugging his pants off.

“Are you sure?” Richard asked, skeptically.

“I need it bad, Tiger.”

He didn’t need any more convincing. They wiggled the rest of the way out of their clothes, and didn’t even try to make it to the bedroom. Richard felt amazing as he entered Candice, his cock like a fiery spear. He began thrusting immediately, hitting Candice’s g-spot with a precision that only an old lover could possess.

She wrapped her legs around him as he pumped in and out of her. He was more insistent than normal, more passionate. At once familiar and new. They didn’t talk dirty, didn’t kiss deeply. It was pure, raw fucking and Candice just laid back and enjoyed the ride. It was wonderful. Candice came first, then a second time as well. Richard was still going.

“Oh God,” Candice said. “God, Richard, this is so amazing. I want it… I’m about to cum again. Cum with me, Richard.” She closed her eyes as her third orgasm began, her pussy gripping his cock. In her head, she saw Kevin. Kevin, pumping in and out of her, spinning her around and fucking her pussy from behind in that changing room stall. As the orgasm reached a crescendo, she remembered how amazing her nipples had felt at 80% sexual, how the air itself had seemed to caress them as they swung in the air. She reached up and pinched them herself, trying to recapture the feeling. It felt almost as good. She felt Kevin climax as well, his cock pulsing as he emptied his load into her. Richard cumming, she corrected herself. Not Kevin. Richard.

She opened her eyes and smiled. Richard was smiling back.

“Wow,” was all he said. He bent down and kissed her tenderly. She kissed him back.

They made their way to bed, Netflix forgotten, and fell asleep quickly. That night, Candice had the most erotic dreams of her life. Dreams of Kevin.