Levi screamed with all his might as Luna’s hand grabbed him. He could see her excited face behind the opening of the washing machine and he didn’t know what to feel. 

As a further insult she peered in the washing machine for a moment and laughed. She noticed all of the wet clothing and took a big sniff. 

“Hmm, that smells nice don’t you think?” she said and smiled. “Do you like smelling like your family’s underwear?” she teased. Luna retrieved him from the dark, wet washing machine and held him under her nose. 

He could feel the wind going in her nose as she smelled him. “Yup, all girly and fresh” she complimented her brother.

“So how was the ride?” she asked and got up to her feet. 

“It was terrible!” he yelled. “How could you do this to me!” he screamed and tried to wiggle free. 

She laughed from the sight beneath her. 

“Uh, terrible?” she asked. “I thought you were the brother that loved roller coasters?” she continued. He stared angrily in his sister’s face as she laid him down on top of the washing machine.

She disappeared from view for a moment and heard her filling the basket. After a few seconds she reappeared and slammed the basket next to him and started to hang her and mom’s clothes to dry. 

Luna peered down for a moment and smiled. “You look so cute in my panties Levi” she said as she picked up another piece. 

She looked at him again and giggled. “You know what would be funny?” she asked. “If I just folded you up and put you in my drawer among my other panties” and laughed. 

“Just letting you wait for a few days until I decide to wear you again” she teased and grabbed another piece of underwear. “Please sis, pick me” she mimicked her brother in a high tone. 

She clearly had fun with the thought. “I think you’ll definitely have to let me do that with you one time, once we’re back home” and laughed while she listened to her brother’s angry responses.

“Don’t worry bro, we’re having way too much to do first before we get to long term teasing” she said and placed the empty basket on the ground. 

She leaned over him and he stared straight at the underside of his sister’s boobs. They wiggled playfully in the air, as if they were looking forward to having fun with his tiny body as well.

She looked down on him and knew his time was up. “N..noo” Luna, he begged as she started to remove him from his panties. He almost wished to stay on them, just to avoid what was coming next. 

He screamed as she lifted him from her underwear and held him in front of her face. He followed her eyes as they looked all over his body. Levi could see she was ready. 

“Now let’s put you in” her voice boomed inches underneath him and his world was turned upside down. 

He screamed obscenities as he saw his sister’s long silicone dildo underneath him. 

She already opened the base and he could see straight into a narrow tube, only some dim light at the end lightened the narrow opening. It was claustrophobic to even look at it. 

“No please, Luna” he begged again, “I’ll do anything, please”, but his sister didn’t listen. She just didn’t care at that moment.

“I know it’s too big for you now, Levi,” her massive voice sounded from above. “I’ll resize you in a bit, just get accustomed ok?” she said and pinned his arms to his side.

He could do nothing but squirm as his face was lowered towards the opening. His screams were unheard by anyone but Luna. He heard her giggle from behind and her fingers shifted a bit around his body as his head went in the opening. 

He felt extremely helpless as light grew dim. “There we go,” Luna said and suddenly let go of his body. He closed his eyes and screamed as he fell down the shaft. His head slammed against something jiggly and knew he was at the tip of the dildo.

Slowly he opened his eyes and he would have barfed if the app would have let him. He saw he was in the shape of a penishead and looked straight down his sister’s legs. Levi followed them back up and screamed when he saw her pussy inches away. 

He heard her giggle again and was lifted above her head. 

Luna laughed when she saw her brother, trapped in her dildo. His face all smashed against the underside, stuck in her own sextoy. She felt a trickle of excitement between her legs. 

She lowered him back down and sealed the dildo shut. Luna bit her lip as she turned her dildo around and felt the little weight inside the toy slam on the underside. 

Levi could just get his bearings and groaned. He looked up and felt incredibly tiny in the dildo. At the end there was light, but the sight was unbearable. Luna licked her lips far above him, ready to play. 

“Comfy bro?” she giggled and he screamed when he felt her walk away.

—

Levi yelled as the dildo slammed against a hard surface below. He couldn’t see anything at the base and wondered where he was. He looked upwards, but could only see the ceiling above him. 

Suddenly something massive moved underneath him and could see the ceiling move. 

“There, perfect” he could hear Luna say in the distance. “Now, where’s my phone?” 

“Ah there it is” she said and he could feel the vibrations as she walked to the other end of her room. He still couldn’t get used to how such simple actions of his sister felt on his tiny body. 

“Now let’s see, what size does he have to be” she wondered and looked at the box that held the dildo. “Ah, perfect,” she said and pressed some buttons on her phone.

He could feel her walking towards him and he felt incredibly scared as he stared at the opening above him. Suddenly her massive eye peered in and he could hear her muffled laugh. He could not process how tiny and helpless he was right now beneath his sister.

“Get ready bro” she said and suddenly he felt himself growing. 

Slowly he grew towards the light above him. As he got nearer, he felt the sides begin to brush against his limbs. “Shit” he thought and tried to move his arms above his head, to have some sort of control, but couldn’t do that anymore. 

“Shit!” he yelled again as he realized he would be stuck in this position, unable to do anything.

Finally, his head neared the clear view at the top of the dildo and he dreaded what he was about to see. The side were now really hugging him, and it was still getting tighter by the second. 

“H-help!” he yelled as he was really pressed in the silicon, until his head finally appeared at the top and he stopped growing. He was completely stuck inside his sister’s dildo. 

He wished it was at least a solid dildo as he could now see his surroundings. He stared straight at his sister, who was laughing uncontrollably. But that wasn’t even the worst thing. 

Levi’s breath stopped as he saw that he could look down at the dildo somewhat and saw she suctioned the dildo on her chair. And he realized what that meant, she was going to ride him! 

The dildo flopped comically as she saw her brother’s reaction in her sextoy. Luna couldn’t help but laugh. “Bro!” she yelled, after she calmed down a bit. “You’re like a little astronaut in a rocket” she said and resumed her laughter at his expense. 

“Well, this is a sight that will get me going” she said after she finally calmed down completely. With a slight last chuckle she sat down on the desk with the dildo between her legs and grinned down at her trapped brother. 

Levi looked at her in disbelief. Her upper body was stretched in front of him, her toned abs decorated her athletic body. He looked up to her face and locked eyes with her. He wobbled inside the dildo and he felt it move with his rhythm. 

He felt extremely scared as he saw his sister’s eyes losing focus. He knew exactly what that meant and slowly moved his head downwards.

He whimpered inside her sextoy when he saw his sister playing with herself. She slowly rubbed her clit as she got herself in the mood. 

He screamed for her to stop, that he was not her dildo. That she could still stop this madness. 

But he knew he was doomed when he looked back up again. Luna held her head back in her neck and moaned as her other hand grabbed one of her boobs. “That’s right,” she moaned. 

Levi felt disgusted by his own sister’s masturbation sounds. He could even hear the wetness on her fingers as she guided herself to higher sensations. 

“N-no, mom!” he yelled. “Dad!” he yelled again, on the top of his lungs. He knew it was futile, but somebody had to save him from this madness. But nobody would come.

“Fuck, I need you in me now!” she yelled high above him. The massive body in front of him suddenly moved at a frightening speed. He could see her muscles work to lift up her massive body.

He almost cried as he saw his sister standing up. Her finger stopped on the tip of the dildo and shook it playfully. 

“Be a good boy and struggle inside me bro” she said and straddled her chair. Luna didn’t even bother to look at him anymore, he was her dildo now. 

Levi looked straight at the wet opening of his sister’s pussy. Her wet fingers spreaded her pussylips to accomadate her new toy. It was a sea of pink and he could see her dark opening in the middle. 

He screamed and struggled as she began to lower down. More and more details were visible as her wet insides approached him. He could hear another moan and finally the lips touched.

They went back and forward on his silicone window, her soft tissue grabbed the toy like it didn’t want it to let it go. It left a layer of her cum around him and he yelled for her to stop. 

Luna didn’t lube the toy beforehand, but her own lubricants would be enough. She was just that horny as she felt the tip of the dildo between her legs. She knew his head was right between her legs and the thought made her crazy. 

She was ready.

Levi begged and yelled, but no help was coming. He never felt so helpless and humiliated as he was now. But he could do nothing as her hips shifted around him. “N..noo, Luna” he whispered as he heard her scream in the distance. 

“Get in now, little bro” she said and began her descent on her new favorite toy. 

He could feel the intense heat through the dildo as it began to warm up the little room he had. Claustrofobia set in and he begged for someone to help him. But he knew it was futile, nobody would come to his aid. He was destined to go inside his sister.

The vision of their once shared room disappeared into darkness, while his sister moaned from sliding him in like a common toy. He was trusted in complete darkness and her muscles squeezed the silicon on his body from all sides. Levi squirmed to get some room and he could hear a loud approving noise all around him. He realized it only gave her pleasure. 

“Incredible” Luna sighed as she completely bottomed out on her chair. She could feel the dildo deep inside her. Luna bit her lip when she felt the dildo moving pleasantly against her insides. She closed her eyes and pictured him inside her. Helplessly trapped in the dark, his only purpose is to give much needed relief for his sister. 

She stayed seated for a couple of minutes. The stimulation was perfect and she knew it would be even better if he was the actual dildo himself. But that would come later, this was his introduction after all. She smiled to herself and slowly began to ride her new toy. 

Levi had never felt so humiliated in his life. He waited scared and alone, for his sister to do something. Finally, after what felt like an eternity, he felt his prison shift and light reappeared once again. 

He screamed for help, for someone to undo his stupidity for practically giving himself to his sister. 

Instead, he was plunged back into darkness as her pussy engulfed him once more. He could hear her scream in pleasure and felt his body bend with her movements. Even if he wanted to move a single muscle, he couldn’t. Her gigantic bottom was stronger than he could ever be. 

Luna began to ride her toy, faster and faster. She bit her lips and slid up and down. “Fuck yes” she screamed as she increased her speed with every trust. 

Her first orgasm began to build and she slammed her ass on the chair. She played with her clit and rode her toy for a bit. Luna gasped with pleasure as she could feel his struggles once more. 

Levi couldn’t take it anymore as he screamed from frustration, anger and disgust. He couldn’t predict one single movement. Her pussy squeezed him relentlessly, and while it wasn’t painful, it only added to his humiliation. 

Distantly he could hear her heartbeat and the sounds of his own sister’s wetness all around him humiliated him to his core. Just when he thought it couldn’t get any worse, he felt her pussy squeezing harder and harder. And he realized what was about to happen. 

He was about to experience his own sister’s orgasm. 

Luna opened her mouth, but no sounds came out. She was this close to orgasm and edged herself, her finger brushed furiously against her clit. Finally, after dominating her tiny brother with her cunt for a whole day, she was about to have her release. 

“Yes!” she finally screamed and came hard on Levi, her tiny little sextoy. Her pussy clamped down on her toy and even now felt his struggles. She pushed her dildo as far into her as she could. Her entire body shook from pleasure, and with a final push, she sat back on the chair. 

Levi’s mind was blank. He was crushed rhythmically from all sides by Luna’s orgasm. His mind couldn’t cope with the realization that his life was reduced to being a masturbation aid for his sister. His body merely a means to an end to send endorphins to her young brain. 

He had almost no time to dwell in that thought as he felt her move again. Within seconds he was in full light again and something heavy slammed in front of him. He opened his eyes and looked straight at Luna's excited pussy. Levi looked up at his sister’s sweaty body and noticed she was out of breath. 

Finally he looked at her face, and she grinned down on him like always.

She whistled. “Wooow, that was incredible” she said and laughed. “No, you are incredible,” she complimented him. “Best. orgasm. ever” she said slowly. 

Luna rested her hand on her belly. She was almost ready for the second round, but she could take her time. Her parents were probably in the pool or something, unaware of her sexual escapades. She felt her body tingle from excitement and how taboo all of this was. 

Luna was ready for round two.

She playfully wiggled her dildo and laughed how uncomfortable he was, stuck in her sextoy. 

Levi never could have imagined she would take it this far. Sure, the last couple of days were terrifying and the panty imprisonment was already hundreds of steps too far. But this won’t go away. However this whole ordeal would turn out, he would always have to cope with the thought that at one point in his life, he was nothing more than his own sister’s dildo.  

“Ready for more?” she teased, as if nothing had happened.. 

Luna didn’t wait for his response, instead she got up and grabbed the sextoy. With a forceful pull, it came off and she immediately jumped on her bed. 

The sight was unreal, as Levi watched her get comfortable against the head of her bed. He was raised to eye-level with ease and could only stare at his sister’s flustered face. Levi begged her to stop, but she just smiled hungrily at him. 

She feigned interest and held him to her ear. “What’s that little bro?” she said and listened. 

Luna couldn’t hear anything, but that was besides the point. “Please put me back in your pussy?” she joked. Infuriated he stared in her mocking face. “Ok, will do!” she laughed and he yelled angrily while she kissed the tip of her dildo. 

Suddenly she spat on the clear silicone above him and he whimpered when she lowered him down. 

She kept looking at him with excitement, right to the point that he found himself in front of her swollen pussy lips. He begged for help as he was plunged forward. He was moved up and down between her lips as she teased herself with him. 

He screamed as he was plunged back into her terrifying wet cave, accompanied by his sister’s wet sounds and moans. 

After a few seconds he was pulled backwards again, only to be slammed right inside her tunnel once more. His body was constricted by the dildo once more and he could only close his eyes and endure his ordeal. He could only hope that she was satisfied at one point. 

—-

“What do you mean, I took things too far?” Luna giggled. 

After her fourth orgasm she had dumped her brother on her naked belly. She figured being rammed inside your sister’s cunt for a couple of hours was enough for one day. 

And she really wanted to hear what he had to say. So far he didn’t disappoint. 

Levi was still enraged. He was plunged inside her for god knows how many times. He could still recall her screams of pleasure. 

For the last two minutes or so he had raged and screamed at her, but clearly she wasn’t fazed by it at all. 

“Because you used me as your fucking dildo!” he screamed. 

The sight before him was unreal. He had to look past her naked breasts in her flushed face. She looked relaxed as ever and her smug grin never left her expression. 

He slammed his fists against her belly in rage, but was only met with a chuckle. 

“Grow me back, now!” he demanded. 

“Oh bro, and lose my kinkiest toy?” she teased. “Naaah, don’t think so,” she said. “Besides, I know deep down you secretly love being your sister's little plaything” Luna teased. 

She put her hand gently on his body so that he would stop his cute little punches. Luna brushed his hair gently. “You know bro, in the end, you’re going to beg me to shrink you down all the time” she teased. 

“And sometimes I’ll will, and sometimes I won’t” she smiled and basked in her power. “But bro” she said and patted his head a few times. “After these few weeks, you’ll admit you like it and this will be a regular thing” she laughed.

Levi struggled between her hand and her soft belly. He hated how he could do nothing to stop her from petting him on his head. Levi could still smell the sweet scent of her sex on her fingers and could only comfort himself with the thought that at least the dildo protected him from her wetness.

“Let me go you crazy bitch!” he yelled underneath her hand. “I would never let you shrink me down my whole life!” he screamed. 

Luna laughed as she felt his miniscule struggles. The power she held over him turned her on once more, but she knew she had to pace herself. Another round of masturbation would be too much on her sensitive pussy. 

“But some light stimulation wouldn’t hurt” she thought and bit her lip. Slowly she turned her brother on her belly so his head lined up perfectly towards the space between her legs.

Levi looked in front of him and saw his sister’s legs. “W..what are you doing” he yelled.

“You know bro” his sister’s voice sounded from behind. “I don’t really feel you appreciate how lucky you are,” she said with a faint hint of amusement. 

“Countless guys offered themself to be my little toy” she said and her hands left his body. Instead two fingers pinched his sides and started to drag him on her belly. 

He quickly realized what was happening, but it was already too late.

“And I said no to most of them, yet here you are” she giggled. “A tiny little brother that shrunk himself so his big sis could have some fun,” Luna said. “Enjoy yourself bro, you’re going to be in there for a while” she laughed and pushed him forward.

Levi screamed and struggled for what he was worth, but within seconds his face touched her clit and was moved even further. 

His head stopped in front of her engorsed pussylips. Her fingers parted them and he stared straight into her pink opening. 

“No stop Luna!” he yelled. But she didn’t care and flipped his body over. Now his whole body aligned perfectly with her vagina, ready to be inserted. 

“See you later bro, have fun!” she said and he screamed when he felt his head pushed inside her opening. Without any efforts he felt her wetness from all sides as her fingers pushed him in. 

His screams went silent as the air was replaced with her wet walls. Her ribbed tunnel glided over him and he felt sick to his core. Within a few seconds his whole body disappeared in his sister’s body. 

He tried to keep his mouth shut as he tasted her fluids. A huge object pressed against his soles and pushed him in even further and realized that it was just her finger.

His eyes were shut and he could only trust his ears, but what he heard was as humiliating as the rest he experienced so far. 

He could hear her heartbeat, the grumbling of her digestive system. And to top it all off, her sister’s excited muffled voice from outside her pussy.

“Comfy bro?” she said happily, followed by three loud slaps outside his humiliating prison. 

“You feel great!” she said and he felt her sitting up.

His body was twisted with the movements of her pussy as she stood up from her bed. Her knees were still weak, but she felt as great as ever. He made a very faint, but nice stimulation in her pussy and she knew he would be perfect there while she enjoyed her day at the pool . 

Levi felt utterly humiliated being stuffed in his sister’s pussy like it was some kind of sick sleeping bag. Her muscles kept him totally immobile as she started walking somewhere. He could not tell what she was doing, but he knew he would be in there for a while as she completely ignored him. 

His body was forced in an uncomfortable position as he pussy slowly began to shrink. The wet walls began to dry up somewhat and with each movement of his massive sister around him, his body was imprisoned more. 

“Luna!” he yelled alone and trapped inside the dark. Stuffed inside his sister’s pussy like some kind of tampon. 

Luna whistled a carefree tune as she gathered her stuff for the pool. After some minutes, she finally exited her room. Completely satisfied from her orgasms and the prospect of hanging out with Jenny and her parents at the pool.

All of them totally oblivious to the fact that deep down her body, her tiny little shrunken brother struggled wonderfully. 

“Hi girl” she said to Jenny, glad that the sunbed next to her was still free. “How’s your day?” she asked. 

Jenny smiled at her friend and laughed. “Had to sleep it off?” she joked. 

Luna chuckled and laid down on her towel. “Yeah, something like that” she laughed and got comfortable.

She took out her phone and loaded the shrinkbox app. “Only one more day for the update” she thought and wondered what it could do. 

Luna laid her head back and loaded the 3D model of her brother. She clamped her pussy muscles a couple of times on her brother and smiled when she felt his miniscule struggles inside of herself.

Something in the app got her attention though. Luna leaned in and tapped her brother’s crotch. 

Jenny frowned at her friend when she heard a stifled laugh. “What’s up?” she asked. 

“Huh?” Luna said, “ah nothing” she shrugged but looked back at the screen. 

She discreetly zoomed in once again to her brother’s crotch on the 3D model and sure enough, the status was the same.

“Fully erect” 

Luna smiled and tossed her phone in her bag. “Good for you little bro” she thought and closed her eyes, already thinking about what she should do next.