Jim, trapped to his armpits in the asshole of his sister-in-law Sarah, began to sob as he recapped the events of the day. In his tears, he began to feel a rumbling in the distance. Screaming for mercy, his mind flashbacked to that morning:

Jim wanted to surprise his wife, Mandi, with the new shrinking serum that has been all the rage. He saved up all his money for months for this surprise. When he finally saved up enough cash, he went and purchased it. He then decided to use it while his wife was at work. He would use the serum and sneak into his wife’s favorite pajama pants. He had bought them for her at Victoria Secret last Christmas. He would wait there until she came home and put him on after her nightly shower. His habit was to lay his wife's nighttime clothes out for her on the bathroom floor by the scale.


Jim stripped off his clothes, put them under the sink cabinet and sat down with his butt next to the pajamas. Opening the shrinking serum he gaze at it for a few moments, hesitating with a bit of fear. Serum was designed to keep you shrunk for a few days at most, depending on your current body mass index. The side effects were the scary part. Very few people experienced it, so it was an uncommon effect, but some people had never returned to their normal size. Of course, the serum had only been out for about three months, so it might just be an extended effect.


Before he could think about it anymore, he quickly drank it like a shot. He started to feel slightly woozy, and passed out.


————————

Jim did not know how long he had been out for when his eyes started to open. It took a second for his mind to come out of a fog, but when it did he opened his eyes with amazement. There he was, probably an inch tall, laying on his bathroom floor. Jim stood up, slight awe and wonder at everything he looked at, and began to walk over to Mandi's pajamas.

With hesitation, Jim lifted up the waistband of the pajamas and began to wander into the darkness. There, he waited...

Jim did not know that Mandi was inviting her younger sister, Sarah, to stay over for the evening. She was a frequent guest in the house. Jim didn't think that Sarah liked him very much, but they always were cordial with one another, even hanging out sometimes when Mandi was not there.

Whenever she came over, it was usually cause Mandi picked her up from work and brought her over. It was her custom to put on his wife’s pajama pants as she chilled at the house. She always said it was to get more comfortable. Unbeknownst to Jim, Sarah was coming over that night for dinner and a movie with them.



As her custom, Sarah went to the bathroom to change into the pajama pants that Jim laid out for Mandi. Jim always hated it when she did that, because it was a gesture that he did for his wife. Mandi never really seemed to care though, even though she would act like she did.

Jim felt the pajama pants rustle as hands began to grab them. He felt a weightlessness as the pajamas were picked up. His heart pumped with anticipation and his breath quickened. He could not wait to surprise his wife by being in her butt. He saw as two thick legs make their way down into the pajamas. He started to get slightly erect as he felth the warmth from the legs radiate to his body he rested in the back-center of the pajamas, perfect position to be launched at Mandi's glorious butt. Something didn’t seem right though. This did not look like his wife’s legs. As the light got brighter in his location he looked up through the opening and saw his Sarahs face. She had not seen him there and the chances are that she wouldn’t. Sarah grabbed both sides of the pajama pants and began to pull them up around her waist.

Jim felt weightless as the rapid assent put pressure on his tiny body. He laid in the middle of the back of the pajamas and he was heading straight for Sarahs asscrack. As he got closer and closer to the round ass of his younger sister in law, the light began to dim as the pajamas began to form around her plump ass. Just as it got pitch black inside his location, he felt the himself slam against Sarahs cheeks, but not just her cheek. Her asscrack. Jim screamed as loud as he could as Sarah adjusted the waist of the pajama pants. As she pulled up on the waistline, Jim was catapulted deep within her asscrack.
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Sarah giggled as she found Mandi's favorite pajamas in the bathroom all set out nice and neat, probably by Jim. Most of the times she liked Jim, though she felt that no one was good enough for her older sister. That is why she came around so often, to make sure that Jim was being a faithful and good husband.

She quickly took off her shorts and top to put on Mandi's favorite Victoria Secret pajamas. As quick as she took off her shorts, the soft, luxurious pajamas came on. She pulled them up her legs and had to give an extra tug around her asscheeks. She has a slightly bigger ass than Mandi, probably because she worked her glutes out a little more than her. She loved how Mandis pajamas looked hugging her ass tightly.

Sarah watched her ass in the mirror as she adjusted the pajamas around her flutes. As she pulled them up, she clenched her butt tight as she felt something touch her asshole. “Wow,” she quietly muttered, “that was weird”

Sarah removed her top and put the matching top of her sister-in-laws pajamas on and went to meet her sister in the kitchen.
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Jim didn’t need to see where he was at to know where he was. A putrid stench, wrinkled skin that climaxed in the middle at a constricting and expanding hole. He had ended up lodged next to Sarah’s asshole. He tried to scream for Sarahs attention to no avail. He was surrounded by too much ass flesh for the sound to pierce through. He was stuck. Jim shimmied his hands to the front of him and placed him on Sarahs asshole. He wanted to push himself away from it if possible. Jim mustered all his strength and pushed. Bad idea. As he pushed on her wrinkly ring, her asshole expanded and his right arm slipped through. This caused Sarah to clench her ass even harder at the strange sensation. Jims arm felt immense pressure and he thought her asshole was about to cut it off. As he felt, in the nick of time, the asshole relented and he was able to pull his arm out.


Jim began to feel the giant mounds on the outside roll around. Maybe because he was so deep within her ass, but the movement did not dislodge him from his location. He was stuck next to Sarahs asshole.


The movement ceased and he could hear faint communication from outside his fleshy prison. His wife and his sister-in-law were having a conversation. He heard them giggle.
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“I see you are wearing my FAVORITE pajamas again, Sarah!” Mandi teased, exentuating the word, favorite sith a hint of sarcasm. “just don’t fart in them this time.”
Sarah laughed, “you should just give them to me, I wear them all the time”
“Well see,” Mandi responded. "But I don't know if Jim would like that. He bought them for me."
“Speaking of gas,” Sarah winked as she stuck her butt out a little bit.
“Oh NO YOU DON’T!” Mandi yelled, eyes wide open.

"Yup!” Sarah said as she pushed out a small fart. It wasn’t too loud, but she made the point.

“Gross!” Mandi laughed. "Put them in the wash when your done with them, or take them home and wash them! I don't want your disgusting farts stinking up my PJ's"
____________________________

Jim heard the conversation, but could not make out the words. He felt an intense pressure surround him. His heart sunk the realization of what was about to happen came into his mind. He used his hands to cover up as much of Sarah’s asshole as he could. He could feel the pressure building on the other side. “NO NO NO NO NOOOOOO!!!!” Jim screamed, tears in his eyes as Sarahs asshole began to constrict and bulge out. “SARAH!!!! PLEASE!!!! NOOOOO!!!!!!”

At that word, Jims world forever changed. It only took a split second, but Sarahs asshole expanded to almost the size of his waist and the pressure that was behind it released. Jim was hit with a force that he never felt before. The putrid scent filled his nostrils and mouth and knocked his head back so hard he thought he may have gotten whiplash. The limited air he had surrounding him thickened. He tried to breath, but every breath that he took filled his lungs with methane. As quick as the asshole expanded, it closed back to its previous size. Jim though, would be forever traumatized by what just happened. He was just on the receiving end of a fart coming from his sister-in-law’s asshole. He took the full brunt of it. The worse part is that she didn't even know he was there. He would never be able to look at her the same way again, even if he managed to get out somehow without her knowing.
_______________________________

Excuse me!” Sarah laughed, bending over in hysteria. “I’m heading to the guest room now to watch some tv. Tell me when Jim gets home so we can get some dinner”

Mandi rolled her eyes at Sarah as she walked away. Sarah was a good sister. They were best friends growing up and now that they are adults, they were practically inseperable. Mandi had blonde curly hair and she had always been jealous of Sarahs wavy brunette hair. It always looked stunning. She also was envous of her athletic ability. Sarah seemed to thrive at whatever athetic activity she set her mind too, while she struggled to stay as fit as her sister. Sarahs toned abs and strong glutes were the envy of all the women at the gym. She saw her sisters ass sway quickly to her guest room where she stayed when she was at the house. She did not know that her doting husband was trapped deep within those cheeks she was gazing at. 

Sarah briskly walked over to the guest bedroom. She ran in and jumped onto the bed, lifting her legs up and placing them on the railing at the foot of the bed. She closed her eyes and began to play with her hair.
________________________________

Jim knew that Sarah must be laying down because his whole world was tossed into a frenzy. On the plus side, he was loosened a little bit from his fleshy prison and he could begin to push away from her asshole. As Jim backed up slowly as not to alert Sarah to his presence, (The last thing he needed was for her to adjust and take away this small amount of movement that he had) Jims foot got caught in something on the floor. He guessed that his feet were on the bed. He could feel a surface below the fabric. Jim shimmied himself into a crouched position to try and loosen his foot from whatever trapped it. His heart jumped with excitement as he felt a hole in the fabric of the pajama pants.

Jim quickly, hopefully not to quickly, brought both hands down to feel the size of the hole. He felt that he might be able to squeeze himself through the hole. He HAD to try. Jim laid down prone and began to maneuver the fabric around his body. He first reached his arms through it and then used the bed fabric to pull himself. He might just get out of this! As Jim pulled with all his might, he saw a glimmer of light beneath Sarahs ass. He continued to maneuver through her asscrack when her legs lifted up even farther than they were already. Sarahs movement freed Jim up from his waist up. He used his arms and the last bit of strength he had left to pull himself completely free.

This movement though was a little to hard.
______________________________

Sarah jolted as she felt something moving down by her asscrack. She quickly reached her hand down to the location and grabbed the item that had touched her butt. As she brought the object to her face, her jaw dropped. It wasnt an object at all. It was Jim!

“WHAT WERE YOU DOING TO MY ASS!” SARAH yelled as she gritted through her teeth. “YOU FUCKING CREEP”

“NO!” Jim shouted. “Please, let me expla...”

“You fucking pervert! How fucking dare you!” Sarah’s voice began to escalate as she began to squeeze Jims tiny body.

“I can....”

“You can what!!!” She retorted quickly. “Explain why you shrunk down to play with my butt!?!”

“Just take me to Mandi, please!”

“NO!” Sarah shouted, giving Jim another squeeze, causing him to yelp in pain. “Mandi doesn’t deserve you! It would be better of if you just ‘never came home”

Jims heart sunk. She could not have just insinuated that she was not going to help. He needed to get to Mandi, then he could explain.

“I’m not going to tell her where you are, or that I found you, you perverted creep. I’m going to keep you with me until I find out how to dispose of you.” Sarah emphatically stated as she lowered her hands a bit. “I need to keep you somewhere though. Somewhere where you can’t get out and get to her.”

“Please, Sarah, it was an accident. I was trying to supr....”

"You seem to like my ass so much, you fucking creep, how do you feel about spending the night with it."Sarah stood up and brought Jim close to her face. "Deep. Inside. It." 

Jim eyes opened with a desperate look of dejection. "PLEASE! SARAH!!!"

She reached her hand around her back. "NOOOOOOO" Jim screatched with every fiber of his being. He had just worked so hard to escape this fleshy prison and now he was going back in.  With one finger, Sarah peeled open the back to her pajama pants and shot her arm deep down into it. She crouched a bit to get a good location.

Jim screamed as he saw what was going on. “PLEASE, SARAH! NO NO NO NO NO NO NO” tears were uncontrollable at this point as he began to flail with panic.

Jim's wiggles did nothing. Sarah’s strong hand had a firm grip on him as she began to force him into deep into her asscrack. He had just spent so much energy getting out of here and now he was going right back. She maneuvered Jim in her hand so Jim’s feet was going in first. At least he might get a better location, he thought. Jim felt his feet hit her asshole, but the pressure did not stop there.

Jims eyes opened in fear and trepidation as he put the puzzle pieces together! “NO, SARAH!!! NOT IN YOUR ASS, PLEASE!!!!!”

His legs easily got swallowed up by the hungry asshole as his body began to get eaten. He was pushed in up to his waist, just when he felt like his whole body was about to get sucked in. She stopped. He was stuck in his sisters asshole all the way up to his armpits. What a humiliating situation to be in. At that moment, the fleshy prison engulfed him once again. He was back.
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A warm feeling flooded through Sarahs body as she felt Jim struggle in her asshole. She felt strangly powerful. A tiny man was now trapped in her asshole with no way to get out unless she allowed him. This thought started to turn her on a bit and she clenched her ass in reflex. This clenching squeezed the breath out of Jims lungs as the enormous asshole constricted on his lungs. This is how I am going to die! Jim thought suffocated by an asshole. 

Sarah moved her waist around a little bit for multiple reasons. First and most importantly, she was getting very turned on and that was the natural reflex. Second, she tried to get used to having a shrunken man halfway up her ass. She arched her back and felt a little pressure build up in her stomach. A smirk lit across half of her face. As soon as she felt it, she released it. This one was louder than her last fart only a little bit ago. The half smile morphed into a full smile across her face as she knew who was on the receiving end of it. She closed her eyes with pleasure as she felt him continue to wiggle around in her asshole.

She may not dispose of him after all, she may just have to keep him.

"Sarah!" Mandi yelled from the kitchen.
"Yes?" Sarah responded with a slight embaressment across her face knowing she had Jim in her ass. Her mind kept telling her that Jim deserved this for cheating on Mandi with her ass, but she also knew that Mandi would be devestated when Jim was never found. For a split second, Sarah thought about giving Jim to Mandi, but it was only a fleeting thought  "I'm coming!" she continued.

Sarah opened the door and  walked out of the room she was in, slapping her ass with satisfaction.