After taking a few moments to gain his bearings, Matt realized he was bouncing between a pair of boobs inside of a sports bra, and looking upwards revealed that his wrists had been cuffed to a long chain. Only an inch tall now, his sister was now wearing him as nothing more than a necklace; based on his surroundings, his character seemed to have just accompanied her on a jog in the scorching summer sun.

He heard the sound of their gate opening, and then he was pulled out of Kirsten’s cleavage and set down on a picnic blanket in the center of their fenced-off backyard. “I gave you your voice back, by the way,” he heard a voice boom all around him, and he turned to see the familiar window into the real world. Except this time Kirsten’s hand wasn’t just down her pants; her shorts had come all the way off, and she was using a vibrator with one hand while her other was messing around with his body’s settings.

“Hello?” he mumbled, as if testing out a microphone, and was relieved when he heard himself like normal again. 

“Hello to you too!” the fake Kirsten beamed as she sat down on the ground, clearly a lot more friendly than the first had been. She tapped something on her phone, and the clasps around his wrists unlatched themselves, freeing him from his role as her necklace. “Jeez, that must’ve been the most I’ve run all year,” she panted, grabbing a full water bottle nearby and downing half of it in just a few seconds. “So, how was the inaugural trip as my new necklace?” Matt was slightly put off by how friendly she was being, but he answered her truthfully nonetheless.

“Not super comfortable,” he answered, wiping the quickly accumulating sweat from his brow.

Kirsten looked confused, “Well it was your idea, but I’ll try and make it more comfy next time.”

Matt rolled his eyes, giving up on the hopes of changing the A.I.’s mind, as friendly as it might appear to be. “Can we go inside, by the way?” he asked hopefully. “It’s so hot out.”

“Ohhhh, lighten up, the heat won’t kill ya!” she answered back. “Why would you wanna go inside when it’s such a nice day out? I think my weather app said it would be in the 90’s today.” As she reached for her phone, outer Kirsten leaned in and increased the temperature with a mischievous grin on her face, and Matt felt the burdensome heat instantly increase. “Oh, looks like it’s 108 degrees, actually,” she said, but shrugged as if it was no big deal, despite her body accumulating more sweat in response to the updated conditions. “Wait, were you asking cuz you’re thirsty? I guess I haven’t fed you since this morning?” Uh-oh… Matt didn’t like the sound of that.

Kirsten stood up and kicked her shoes off, slipped her socks off and tossed them on the blanket, and then shimmied her spandex shorts off along with her panties. After pulling her bra off too, she was left standing completely naked in front of her confused (and moderately scared) brother. Then out of nowhere, the heat increased again by almost 30 degrees, as Kirsten had set the simulator’s temperature to 136, the hottest the Earth has ever been, while also switching on an option to prevent any liquids from evaporating—including sweat. Within literal seconds, the giant version of Kirsten’s body became so covered in sweat that it honestly looked like she’d just gotten out of a pool. Her workout clothes were sopping wet now, completely drenched in her perspiration as a non-stop trickle of sweat droplets dripped off of them.

She set her bra down next to Matt with the cup facing up—it wasn’t a particularly deep one since it was athletic wear, but it seemed incredibly deep compared to Matt, who was then deposited directly into the center of her cup. But the scene only got worse for him, as she held her dripping shorts and panties above his head, and then twisted them tightly, allowing a huge stream of murky sweat to rain down on Matt and puddle at his feet.

Kirsten arched an eyebrow at him. “Is something wrong? Why aren’t you drinking it?” she asked in a genuinely innocent tone.

Matt’s eyes bugged out as he heard what he was supposed to do, and he turned to his sister out the window, shaking his head. “There’s no way you’re gonna actually make me go through with this, right?”

“Oh, I’ll make you go through with it,” outer Kirsten grumbled, and leaned forward to tap the Autopilot button. “Whenever you complain like that, it ruins the mood.”

“What do you mean?” inner Kirsten spoke up. “It’s the same sweat I always give you for lunch.”

Matt was about to make his retort, but instead of saying what he was thinking in his head, he heard his mouth instead say, “I was just kidding! Thanks, Kirsten!” Against his own will, the program forced Matt to drop to his knees and cup his hands together, dipping them below the surface of the thick, warm fluid. It even put a smile on his face while he was doing it, yet in his brain he was trying everything he could to take control of his body again. But he just couldn’t, and soon enough he brought the helping of sweat to his lips and drank it all down without so much as hesitating. It was unbelievably salty and obviously tasted putrid, but he couldn’t stop himself from drinking more cupfuls of his sister’s sweat—and of course the plentiful salt just made him actually thirsty, which just made the problem seem even worse.

He heard outer Kirsten typing something on her keyboard, and then proudly  slam the enter key, prompting Matt to open his mouth to say the custom dialogue she’d input for him: “Can I drink it fresh from the source please, mistress?”

“Of course!” she grinned, picking Matt up before laying down on her stomach, kicking her feet up behind her, and setting him down on her back. She sighed contentedly, blissfully enjoying the scorching, impossibly hot sun that beamed down on them, and Matt’s character almost slipped on all his sister’s sweat as he made his way towards her ass. On his hands and knees, he crawled into the valley of her butt crack, where a slow and steady stream of her sweat was trickling out of, and leaned down to gratefully slurp up the fresh, hot ass sweat as it oozed his way. 

Matt couldn’t see his real sister anymore, but he could hear sounds of her pleasure echo all around him as she watched her tiny brother forcibly drink a never-ending buffet at the gates of her ass. Only after several minutes of playing with herself—several grueling minutes of nauseating torture for Matt—did she finally skip to the next video, saving her brother from his plight but leaving him to wonder when it would end.