Scott grunted as he rolled Jackie’s dumbbells over to her, directing them to the space in front of her feet one by one. She scrolled through her phone absentmindedly, doing her best to manage her social media pages on her breaks between sets. With her water bottle in her other hand, she took a sip before holding it out for Scott to grab.

Panting as he finished moving her dumbbells, Scott looked up to his giant stepsister - waiting for him to take her water bottle. “Well?” she asked impatiently, finally sparing him a glance as he stood up straight and reached out to take it from her.

“Sorry, Jackie!” Scott quickly replied, taking the bottle and closing the lid for her. He stood nearby, taking her phone into his other hand as she passed him it. He waited patiently, knowing she’d ask for both of them back immediately after her next set.

The huge girl sighed as she stretched, psyching herself up for her next set. She smiled at Scott’s obedience, accepting that he wouldn’t get everything perfect so soon, “It’s fine. Just try to be on the ball next time. Having a little assistant to help with my influencer career is going to make things SO much easier!”

“It took a little to convince Mom to convert this room into a gym.” Jackie explained, grinning at her brother as she continued, “It might take a little more convincing to make this arrangement between us permanent, but I think she’ll come around when she sees you can still be useful.” Scott watched as his stepsister bent over, her oversized ass sticking out in her yoga shorts as she plucked the dumbbells up from the ground before her.

Scott couldn’t tell if it was another way for her to demonstrate the size difference between them, or if she was simply being nice when she gave clothing that fit him. They certainly were a lot better than the dress-like tee he’d thrown on, but he couldn’t help but feel at least a little humiliated over being given a crop top to wear. And for his bottoms, she had cut the leg off an old pair of leggings and threaded a shoelace around the waist of it. This created what was a somewhat loose though reasonably fitted black skirt.

He watched as Jackie threw the dumbbells up over her shoulders, keeping a strong core as she lowered herself into a squat. She looked enormous, layers of thick fat caked on top of what could only be described as slabs upon slabs of dense muscle. Her large breasts were well contained by her sports bra, the fleshy edges still teasingly fighting to escape from the tight fabric's grasp.

Scott couldn’t tear his gaze away from her as she lowered herself into a tight, deep squat. Her entire physique was breathtaking, her assets jiggling uncontrollably from just the slightest of movements, even as she tensed her muscles. With a deep breath, she blew the air out as she rose back up into a standing position. “One!” she grunted, before slowly allowing herself to drop back down.

As she finished up her set, she gently placed the dumbbells back down on the ground. “Towel!” the huge girl commanded, prompting Scott to step forward. Crouching down, she took his crop top into her hands, wiping her slick brow before stretching it to reach beneath each armpit and dabbing them too. Bringing her nose down to her right armpit, she sniffed, “Urgh, already starting to stink! I wish there was a way for a fun-size bro like you to help with that too,” She laughed.

Scott wanted to gag, feeling the increasingly moist fabric cling to his skin. At least what she wore was breathable. His clothing was soaked with her ripe, stinky sweat. As she continued her workout, she decided to move onto curls. “Bro, can you grab me the 25s please?” she asked, scrolling through her phone as she waited.

Making his way over to the rack, Scott found the 25s and tried his best to lift one, having no success at all. He looked over to Jackie, who still hadn’t noticed his complete and utter failure, and tried again before she saw. Still no luck.

Wondering why Scott was taking so long, Jackie looked up from her phone only to see the puny guy frantically try to pull the dumbbells off the rack. “Ha! Don’t hurt yourself, little guy.” she laughed, making her way over to him. Lightly grabbing his shoulder, she pulled him close and tightly grabbed onto the bottom of his shirt and waistband of his makeshift skirt. Scott grunted as he felt both items tighten against his chest and waist, her fist now wrapped in a coiled wad of his clothing.

Jackie joked, “I think you might weigh a tad less than one of those dumbbells! Now straighten up your body so you’re not so limp.” Scott looked up at his huge sister, humiliated as she so easily lifted him in one hand. Reluctantly straightening his body, Scott felt the tightness in his abs from holding the position. He looked up at Jackie as she did her first rep with him, curling her arm towards her shoulder, her bicep swollen and tense.

Scott felt his stomach lurch slightly as she lowered him, giving him very little time before she lifted him again, grunting as she did. His face flushed red with embarrassment as he watched her continuously lift him, her hot breath washing over him as she panted, seemingly paying him very little mind now that she was in the zone.

As she reached ten reps, she lowered the tiny teen down to the floor beside her other dumbbells. Placing her hands on her hips, she looked down at him, “Right, that’s a good burn but we’re not quite there.” She assessed what weights were available to her, “So we’ve done 25lb now, I have one 20lb dumbbell and one 15lb dumbbell…”

Jackie’s eyes widened as an idea came to her, her face of concentration turning to an excited grin, “Okay! Little bro, you’re gonna help with my drop set.”

Scott looked back at his eager sister, asking, “Okay, so what do I need to do?”

Chuckling to herself, Jackie replied, “Well…you're not small enough just yet…”

Scott cried out, “Please I’m begging you! Don’t make me!” Tears filled his eyes as he desperately looked towards the door for an escape, contemplating how much time he’d have to open it if he bolted.

Jackie looked over to the door, realizing the stupid thought that ran through her brother’s head. “And don’t even think about it,” she warned, tightly gripping his shoulder in her left hand to cease any attempts before they started. “That would be a really stupid thing to do, don’t you think?” she asked, her small attempt at training him from even thinking of such a thing.

“Go ahead and test my patience. Maybe I’ll go down the street and talk Big Old Sue into a trade ‘til mom gets back...” Jackie threatened, her brow pointed maniacally as she maintained her grin, “I’d have to get you down to under a foot tall first. The same size as a nice, fat dick. Perfect for lonely, old Sue, don’t you think? You’d be right at home wouldn’t you perv? Getting plunged in and out of her big, messy cunt. Night after night.” Scott’s face was one of sheer horror as he looked up at his sister, wishing he’d never even looked at the door. She continued, “I bet she’d just LOVE to have you. Is that what you want, little bro?”

Scott fell to his knees, Jackie’s grip on his shoulder slipping as his tee came away from it as he fell. She looked down at him with the shoulder of his shirt still in her grasp, pitying him, as he cried and begged, “Please don’t make me too small, Jackie!” He coughed, letting out a painful sob as he panicked, thinking he was about to be less than a foot tall already.

“Aren’t you listening, dweeb?” she asked, raising one brow at his overreaction. “I’m going down to 15lbs,” she explained, “So I can’t have you getting too small on me just yet. What would be the point in lifting such a puny thing?”

Scott could only watch as his huge stepsister got on her knees, pressed her hands firmly against his chest, and pushed him down on his ass and back. He brought his chin to his chest, watching her every move as she ran her tongue across her dried lips. Pulling his skirt from the bottom, she lifted it over his hips to expose his limp cock.
 
Jackie smirked at her brother as he looked away from her in dismay, not wanting to see what was about to happen. He winced as he felt her huge fingers grip his dick, fiddling with it as it flopped around. Lightly gripping his shaft between her finger and thumb, she tugged. Almost immediately she felt it stir, growing full mast in just a short amount of time.

Not wanting to leave much for recovery time, the huge young lady wasted no time in leaning towards the stiffening member. She eagerly wrapped her lips around it, swirling her tongue along the sensitive tip. Jackie gobbled down his whole length with ease, resting upon her tongue like a small morsel of food she was about to devour. Pulling her head back, she withdrew its entire length, all but the tip.

Looking up at her brother, she watched as he dug his face into the carpet, writhing in pleasure already. She chuckled to herself as she gulped down his cock once more, working head into a pumping rhythm. Using her free hand, Jackie expertly grabbed his balls and started massaging as she sucked.

It took virtually no time at all for Scott to reach his peak, that much was obvious to Jackie. His testicles tightened, signaling to her that they were about to shoot his cum out through the throbbing cock she currently sucked. And who was she to say no? She eagerly sucked, lightly squeezing his testicles as they pulsated, sending his cum out of him in periodic spurts.

Jackie felt his minute amount of cum squirt onto her tongue, the salty taste present to her as she swallowed. “Mmm,” she sounded simply, siphoning up the excess cum and moisture from his cock as she withdrew her mouth. She stared in fascination as he shrunk down before her, losing a few inches from just that release. Jackie couldn’t imagine this ever getting old.

Standing back up, she commanded, “Okay, let’s go. I have a workout to finish!” Scott nodded, shakily climbing to his feet in front of her. He tried to pull the skirt down over his exposed, still dripping cock, unable to do so as Jackie reached down and tightly gripped the clump of his clothing she had previously used to handle him.

He moaned in discomfort, humiliated as his giant stepsister lifted his entire body into the air like it was nothing. She grabbed the other 20lb dumbbell and bobbed side to side slightly with them both in hand, “Hmmm, seems about right to me!” Jackie proceeded to curl him and the other dumbbell, maintaining excellent form as she easily pumped out a set of fifteen reps.

As she placed him and the dumbbell down on the ground, she commanded, “Towel!” Having forgotten his other duties, Scott paused for a moment before remembering and stumbling towards her. He held the edge of his tee out to her, waiting for her to grab it. Crouching down, Jackie gripped the tee, wiping her face and pits once more.

The huge girl sighed, “That was a good set. Now for the set of 15s.” She looked down at her brother as he tried his best to wring out the soaked fabric he wore, “It’s only going to keep getting wet. Just leave it.” He released the tee quickly, allowing the now creased fabric to fall against his stomach.

Pushing him down to the floor once more, Jackie got onto her knees and hovered ominously over her brother. “Now try not to cum too much, I need you at 15lb, not less,” she stated, getting no reaction other than a defeated whimper as he lay there static.

She looked down at his soft cock, white flecks of his dried cum staining the tip. Opening her mouth, she closed the gap between them, engulfing his limp member. As her tongue rolled across his tip, she got a taste of his dried cum liquifying in her mouth. It took a little longer to get him hard, having just orgasmed not long ago, but he became hard nonetheless.

Like some sort of sick, sexual ritual, Jackie proceeded to suck him dry. Quickening her technique as she caressed his swollen testicles, trying to encourage them to do her bidding. With his cock still in her mouth, she mumbled, “Come on bro, I need you a little smaller. Why don’t you just cum for Big Sis?”

Scott squirmed beneath her, painful pleasure coursing through him as he tried to think about anything except the overstimulation of his cock, too soon after the orgasm before. His huge stepsister swirled her tongue around, not swallowing any of her salivae as she allowed his cock to stew in the warm spit that pooled in her maw. Up and down she bobbed her head, orally molesting his stubborn member. Jackie panted from the ironic workout within a workout. Using the back of her hand to wipe the sweat from her brow, while the other jerked him off, Jackie paused for a moment to make eye contact with her captive. “Come on bro, you like being small don’t you? Just think of how big my fat ass and jiggly tits will look when you’re just a little bit tinier. It’s okay, just let go, bro. Cum for me.”

She miraculously felt Scott’s cock harden in her grasp as she went back to sucking. Shocked that it had worked, she immediately felt his balls tighten in her other hand and, like before, he came into her mouth. She slurped up the excess as she withdrew, watching him shrink down to what she assumed to be only around two and a half feet.

“Towel!” she exclaimed, watching him struggle to scramble to his feet to hold his shirt out to her. Still crouched, she took the edge of the damp tee and wiped the tiny amounts of cum and saliva from the edges of her mouth. “Thank you,” she said simply, standing back up.

Reaching back down to him, Jackie wasted no time in grabbing him once more, keeping his clothes in the tight coil that allowed her to keep him rigid while she lifted him. She grabbed the 15lb dumbbell and assessed their weights, noticing that Scott was perhaps a tad under 15lbs, but it would have to do.

Scott did nothing, feeling the tightness on his chest and waist, as Jackie lifted him. He counted each rep, eager for her to stop. He sighed in relief as she reached her fifteenth rep, panting heavily as she held him and the other dumbbell up in the curled position. Her hot breath washed over him as she uncurled. Expecting her to lower him to the ground, Scott was shocked to find himself being curled once more. He moaned in frustration, manhandled by his enormous stepsister as she banged out an additional fifteen reps.

Upon reaching the peak of her thirtieth rep, Jackie let out an aggressive scream, carelessly dropping him and the other weight. Scott came crashing down to the hardwood floor, gasping for air and feeling like he had broken a rib as the other dumbbell bounced in place. Jackie looked down at him, smirking at first, before realizing she had truly hurt him. Her face turned to a genuine apologetic expression, “Sorry little bro, I just got caught in the moment, working until failure ‘n all.” Placing her hands under his armpits, she stood the small teenager up, “You’ll be fine, you’re just winded.”

“Just give it a moment,” Jackie explained to her heaving brother, barely able to stand as he clutched his stomach, winded. As Scott finally caught his breath, he looked up directly into his sister’s eyes. In a sudden outburst, he screamed, “What the fuck!? You giant bitch!”

All of a sudden Jackie’s face turned stone cold. Everything went red for her. “What the fuck did you just call me?” she spat down to him, feeling her face flush with raw anger. She closed the gap between them, looming over him as he immediately curled up into the fetal position, trying to protect himself from the oncoming storm.

“Come here!” she shouted, grabbing his shirt in one hand and lifting him off the ground. She stomped into her room, carrying him with her, wiggling and whimpering. She terrified him to the point where he feared any further protests would make matters worse. As she shut her door behind her, she tossed him down onto her hardwood floor, winding him once more as he slammed against it.

Scott slowly clambered to his feet, watching Jackie glared at him as he did. “Bitch huh?!” she asked rhetorically, clenching her teeth in anger as she approached him. “I’ll show you who’s the bitch!” she shouted, soccer kicking him in the stomach. She watched as he slid across the floor, gripping his stomach in pain as he writhed and wailed. It was like nothing he ever felt before.

She tutted at his weakness, which was half-tilt at most, and here he was crying like an infant. “Stop being a baby and take your punishment!” she said, turning him over and straddling him. She held him in place with her left hand as she cocked her right hand back, fingers splayed. Scott winced as the hand came down towards him, smacking him full-force across the face, giving him whiplash in the process.

Situating him once more in position, she wound back for another. And another. Again and again, she hit him. Smack. SMACK. Quickly drawing blood as he lay beneath her, balling and begging, “Please don’t kill me, Big Sis! I-I’m so sorry!” His sore mouth barely formed full words, every attempt to beg a stuttering mess, “I… I’ll go far, far away! You’ll… You’ll... n-never have to see me again. I’ll f-find a shelter, go camp in the woods... anything! Just please stop, I don’t wanna die!” He broke down into a terrified wail, having no further words to save him as she relentlessly beat him.

Jackie, still holding him down, felt a wave of emotion consume her. Deep, bottled-up feelings she never addressed. Her face, no longer filled with rage, looked down at him in pained guilt as tears began to well up in her eyes. She lifted her crying and begging stepbrother, shushing him and cooing, “It’s okay. You’re safe now.”

Holding him like an infant, she climbed into her bed and cradled him in her arms. Scott whimpered in her grasp, his eyes clenched shut in fear as tears and blood coated his face. He listened to her heartbeat as it slowed, calming him down. Looking up at his brutal captress, now seeming less intent on hurting him and perhaps even regretful for having done so, the horrified Scott asked, “You’re… You’re n-not gonna kill me?”

Jackie looked down at him, with what he thought was an offended look. He winced, expecting her to hit him again when instead she began profusely apologizing. “Shhhh…” Jackie cooed back to him, lightly placing her hand over his mouth, “No, stop, you have nothing to be sorry about.” As he calmed, she lightly stroked his hair, “I know I can never take back what I just did to you, what I’ve been doing to you…” Jackie burst into tears, unable to hold it back any longer, “But there’s something I need to tell you.”