Ady's teeth clenched and his muscles bulged as he strained – and he wasn't even in the gym yet. With a final pull, the gray wolf at last got his gym shorts up to his waist around the immense bulge of his package, pushing at the fabric from within and leaving nothing to the imagination. His huge, potent balls were clearly outlined and his cock even more so, but that was the reason he'd come to this gym in particular: it advertised itself as being hyper-friendly, so the unmissable bulge he was packing wouldn't be a big deal. Exhaling, he leaned against the lockers next to him for a moment to recover, quickly pulling on a plain tank top before stashing his bag inside a locker and making his way out of the changing rooms and into the gym properly.

Fortunately it was pretty quiet today, though not completely empty. Over at the treadmills, a rabbit with immense tits was jogging on one, her chest bouncing and wobbling with every step she took so much that it was amazing her stretched-out top could stay on her. At the weight rack, a musclebound dragon man was lifting a barbell that Ady wasn't sure outweighed the man's own huge bulge. A possum woman was using a jump rope as part of a warm-up, her heavy tits bouncing along with her, and a red fox doing squats while watching a football game on the wall-mounted TV had such a huge sack that it touched the ground every time he lowered his hips.

Finally there was a gray fox who stood out from the others for a number of reasons, not least of which was the fact that she had two heads, but being seven feet tall certainly helped too. Ady couldn't help but stare briefly: she was wearing a two-piece gym outfit that was pink on one side and white on the other, the top and bottom pieces mirroring the design. When she turned, he saw that she had a lanyard resting on her double-D breasts – a size that seemed almost modest compared to the other patrons. Yet she also had a notable bulge in the lower half of her outfit too, outlining a heavy sack as well as a sheath, including the tip of a canid cock peeking from it. She wasn't entirely light gray either: her right head had much darker hair, contrasting the light gray on her left head. A long streak of black fur covered the underside of the right head's muzzle, ran down the right half of her torso over one breast, and went between her legs, covering one inner thigh.

Her right head wore a small pair of gold, square-framed glasses, and her gaze – or at least the right head's gaze – met Ady's briefly. The left head then looked at him too, and they talked to each other quietly before wandering off, heading through a door marked 'Staff Only'. A little bemused, Ady shook his head and put it out of his mind, ready to get to work on his own routine.

Even here, the gym-goers were much like anywhere else, keeping to themselves and paying him no mind, so his workout went smoothly: a warm-up, some bodyweight exercises, a number of sets at the free weights, and a bit of time at a leg machine, where his thighs hefted up his junk every time he raised them. While he was working out, the others kept to themselves, with other gym-goers coming and going, while the two-headed fox he presumed was the manager periodically came in, checked the place out, and left again.

Ady was so focused on his workout that he easily lost track of time, more concerned with counting his reps and remembering which set he wanted to do next. When he was done, he felt exhausted, but in a good way, and drank everything left in his water bottle between cool-down exercises before heading off to the showers...

...or at least, that was his plan.

The 'Staff Only' door opened once more and the manager came out, approaching him directly on his way to the showers. Ady looked back over his shoulder; had he forgotten to return a weight or something? But no, he'd remembered to put all the equipment back...

"Excuse me," the head with the black underside addressed him.

"Uh... something wrong?" Ady asked cautiously.

The lighter-colored head gave a chuckle. "Nah, we just like to get to know our patrons, and we haven't seen you before," she explained with a smirk. "I'm Jessie, and this is Jennie, but you can just call us Jess and Jen for short."

Their right arm raised and waved to him. "Hi there," Jen greeted him.

"Hi," Ady replied, giving a small wave of his own. "I'm Ady."

"Good to meet you," Jen replied, her gaze flicking down to his loins as she adjusted her glasses.

"So how are you liking the place?" Jess asked, "Find everything you needed?"

"Yeah. It's pretty great. I can't go to my old gym any more 'cause, well..." He gestured to his crotch.

Jess just grinned while Jen giggled and said, "Oh, that's not a problem here, as you've seen! Hey, tell you what, since you're new here, I'll let you use my private showers instead of the shared ones, how about that?"

Before Ady could even answer, the wolf leaned forward and, with surprising strength no doubt aided by her much greater height, simply lifted him off the ground and slung him over her right shoulder. "Whoa, hey!" he blurted out, but her arm had him held in place, the bulge in his gym shorts pressing up against her tits as she walked off with him.

"Don't worry, Jen is very gentle," Jess reassured him, reaching out and opening the 'Staff Only' door for her other half.

"I am!" Jen agreed as they made their way into the office. It seemed fairly normal as offices went, other than the open bottom drawer of a filing cabinet being stuffed with sex toys, but Ady didn't get to look at it for long before he was carried through into a tiny version of the locker room he had been in before: there was a single shower stall, a very small bench, and exactly two lockers. Jen set Ady back down on his feet, before bending down and taking him by surprise as the fox's right hand grabbed the back of his head and held on as she locked lips with him, making out passionately.

Jessie gave a chuckle, apparently controlling their left arm as she reached out and slipped her fingers under the waistband of his gym shorts. "You're pretty handsome," she crooned to him, trying to tug his shorts downwards and having trouble from how tightly stuffed they were. "Mmm, and really hung... you know, we do sell hyper-friendly outfits here, you should take a look later..."

Jen separated her mouth from Ady's briefly to chide her sister, "Jess, don't try to do the sales pitch, I'm busy here," before immediately resuming making out with Ady, pushing her tongue into his mouth. For his part, once he got over the shock he was eagerly returning the gesture, though his cock stirring wasn't helping Jess to get his shorts off. With a final heavy tug she managed to pull them down, leaving him in just his briefs. They contained his immense package much more comfortably, and Ady even gave a groan of relief into Jen's maw as the pressure around his loins was relieved.

"Oooh, looking good so far," Jess remarked.

Jen pulled away again, leaving Ady in a little bit of a daze, a strand of saliva briefly connecting their tongues. "Let's see the rest of him," she asserted, and together they grabbed the bottom of his tank top and pulled it up and over his head. He obligingly lifted his arms to let them remove it, and they tossed it aside, admiring his physique now that his chest was bared.

"He's a real cute one," Jen said to her other head.

"Agreed," Jess teased, "Though we should show him what we have to offer too, don't you think?"

Jen nodded and reached out, pushing Ady back and making him sit on the bench. He sat and stared as the fox backed up and pulled off her top first, having to lift it on one side and then the other to account for her dual heads, her breasts bouncing freely with the large pink nipples standing firm already. She then moved on to the lower half of her outfit, pushing it down on one side and then the other, this time just to put on a teasing show than for any practical reason. It fell down to her ankles to reveal her black-furred sheath over an identically colored ballsack, the orbs within resting on her thighs. The tip of her cock was already sliding out, pointed at the end in canid fashion, and their right hand reached out to tease her growing pink flesh briefly. She then turned around, raising her tail and showing off to Ady, flaunting the fact that she was a full herm with a feminine slit located behind her sack, their left hand reaching back and pulling the labia open just a bit to show the pink flesh beyond.

Ady very much enjoyed the show, and his briefs were being stretched as his cock swelled. Turning back to face him, Jess and Jen approached, both arms reaching out. "We'd better help him out," Jess said to Jen while they tugged down his briefs, having a much easier time getting them off of him despite the obstacle his hardening flesh posed. Jen gave an appreciative hum and Jess whistled as his cock and balls flopped free, the end of a string of beads sticking out from his dick just a little bit.

Jess put her left arm underneath Ady's cock and hefted it up, feeling along his urethra where the beads were bugling it out. "Well, well, someone brought some equipment from home, hm?" she teased, while Jen's right hand was busy holding and stroking her growing shaft as she admired his package.

"Yeah..." Ady admitted, panting a bit. "I didn't want to... leak pre everywhere..."

"These must be very productive, then," Jess said as she slid her hand down to his sack, cupping one of his huge balls and stroking over it.

Jen chuckled and grinned deviously, leaning her head over to rest on the side of Jess's. "What if I made them even more productive?"

"Ooh... are you thinking what I'm thinking?"

"Pretty sure I am!"

Ady was a little lost as the two giggled together – but then Jess held his throbbing flesh steady while Jen gripped the end of the bead string and pulled it out. One by one, each bead popped out from the end of his urethra, and he moaned in response, his hands clenching and his toes curling. When the last bead was tugged free, a large amount of precum spilled out from his cock and splashed onto the floor, continuing to leak steadily even after the initial surge.

"Whoops!" Jen exclaimed, dropping the beads and grabbing his arm instead, pulling him to his feet. "Don't know what I expected, really. Let's get him into the shower so we don't make a mess all over the place."

Jess grabbed him too and guided him into the single shower stall, pressing him up against the back of it while he was still dazed from having the beads removed. His cock was fully hard now, and Jess went back to holding and stroking its underside, and he took the opportunity to catch his breath.

Then suddenly he felt something against the end of his cock and his eyes shot open, looking down to see Jen holding their dick, lining it up with his own much larger member. She was able to easily slide inside with all the slickness from his pre as well as from his urethra being so recently stretched, yet Ady noted – barely, on account of the intense sensation of having his shaft penetrated – that only Jen moaned out in pleasure as the two-headed fox buried her length within his own.

She slid in all the way, including the uninflated knot at the base of her cock, and Jen moved her hand to grip just behind the crown of Ady's glans while Jess held him further down. "Ooh, look at his face," Jess remarked calmly while Jen began thrusting, the fox's black balls swinging forward on each thrust. "He's loving it."

"Mmh, so am I!" Jen groaned out, her eyes shut tightly behind her glasses as she rocked their hips back and forth. Each time they pulled back, more precum spilled out from the end of Ady's dick, and the plentiful slickness let them keep a rapid pace. Ady could only lean back against the wall of the shower, hands pressed against the sides to help keep himself steady, his eyes barely able to focus as he stared at the duo's bouncing breasts as they fucked his cock, Jess with a smug expression as she observed while Jen felt all the pleasure.

Before long Jen inhaled sharply, and Jess chuckled. "Oh, oh, she's gonna blow," she warned Ady, who barely registered her words through the haze of pleasure, lost in the sensation of the cock thrusting into his own. "Go on, sis, give him a good one." Soon after, Jen did exactly that, thrusting in fully – and Ady let out a surprised cry as she knotted his glans, the bulb of flesh at the base of her shaft now inflated. Her entire length throbbed and pulsed as Jen moaned out in bliss, her balls pulling up and unloading into him, and with her knot sealing his urethra, all of her cum flowed into him – and down into his balls.

His already-heavy orbs bulged and swelled as they took on her load, hanging lower and heavier in his sack. Both of her hands held his dick steady as the fox's nuts pumped his own fuller and fuller... yet the moment her orgasm ended, she pulled back, popping her cock out from his with a wet slurp as the knot exited, making him shudder and groan.

And then she pushed it back in.

"Ohh fuuuuuck," Ady groaned out as she went for a second round immediately, sometimes knot-fucking his shaft by shoving herself fully into him and then pulling back out, sometimes electing for shorter thrusts instead to go faster. She moaned out heavily, panting along with him, and Jess at one point had to reach up and straighten her sister's glasses so they wouldn't fall off from how energetically Jen was thrusting into his dick.

"I should've warned you," Jess remarked casually as Ady's eyes rolled back and stared at the ceiling, his mouth hanging open, "She's got a lot of stamina!" He could only shudder and groan in response, feeling all the extra weight in his sack as his balls churned with both his load and hers. Every time her knot popped into him he let out a moan that echoed off the shower walls, and each time she pulled back more pre spilled out with a little bit of her cum mixed in, splashing into the shower's drain.

When she came again, both of their hands gripped his cockhead directly, squeezing it around the knot Jen had forced inside once more. Again, he felt her cum pour into him, an orgasm just as potent as the first one, filling his balls even more. They hung down past his knees now, getting bigger and heavier with every moan from Jen accompanied by another thick gout of cum she unleashed into his cock.

And then she kept going. Every single thrust now, Jen pulled her knot back out, then shoved it back in, going slowly but thrusting with almost the full length of her shaft. Ady was tingling all over, his hot, hard flesh throbbing around theirs, leaking heavily every time she pulled out. And Jess continued to observe, holding his dick while her sister kept plowing it, letting Jen fuck him to her heart's content.

Her third orgasm made her mouth hang open with her tongue lolling out, another powerful climax erupting into him. His sack sagged and he gasped between his moans when he felt the bottom of it resting on the floor of the shower from how big and heavy it had gotten, several more pumps of her cum swelling it even further before she was finally done. "All good?" Jess asked her sister, and Jen panted heavily, nodding in agreement, while Ady was left in a haze of pleasure mixed with the intense desire to cum after going so long without an orgasm of his own.

"Good," Jess continued as Jen pulled back, her knot easily popping free now. "It's my turn. I've been waiting long enough..."

The fox turned around and Ady barely registered what they were doing until she backed up to him and she wedged her pussy against the tip of his shaft. She certainly wasn't kidding; she was leaking heavily, her inner thighs heavily wet with juices, and this time as she sank back onto him and took his cock into her folds it was Jess who moaned out loudly while Jen merely continued panting in recovery. Ady shuddered heavily as his huge girth spread out her wet vaginal tunnels, surrounding his sensitive flesh in slick warmth.

Jess certainly seemed to have just as much eagerness as her sister, as she sank all the way down onto his cock even as it reached the limit of her depths and started making a prominent bulge in her belly. The way she moaned indicated how much she enjoyed it, and right after her hips bumped his, she started pulling back, her right hand gripping the corner of the shower stall to give her leverage to pull herself with. Through half-open eyes Ady watched in a daze as she rode him, yet it was hard to focus at all as his pleasure began mounting after being denied a release for so long. His balls churned heavily, desiring a release after being filled so much, resting on the floor and against his own legs; it was a good thing they were about to be drained or he would have been stuck...

"That's it... ride him..." Jen panted to her sister as Jess rammed her hips back against his own again and again, his entire length covered in pussy juices and glistening each time she pulled back. He gritted his teeth and shut his eyes as he felt his climax building up, all while Jess moaned in pleasure, and he felt their left hand rubbing over the bulge in their belly that his huge shaft made each time she took him into her...

He couldn't hold out for long and let out a cry as he finally reached his orgasm. It was like a fire hydrant bursting as his sack tensed, so heavy it couldn't pull upwards, his urethra bulging out as the mixture of his cum and hers surged back out of it and into her pussy. The first shot alone was so potent that it almost pushed her off of him completely, her belly bulging out even as a large amount of jizz spilled back out from her and splattered on the floor of the shower. Eruption after eruption of cum surged out from him as he shot all of her cum into her, with his own added to it, his mind blown by the intense pleasure as his balls clenched repeatedly, gradually shrinking down.

Yet as his sack lightened, her belly grew immensely, even with all that gushed back out from her. The vast amounts of cum he pumped into her bloated her out, so much that even Jen was moaning along with Jess as she was swelled full of thick, hot cream. It was enough for Jess to reach her own peak, almost screaming in ecstasy as her walls tensed and rippled along his cock, only pleasuring him further and making him cum harder. She trembled, struggling to remain standing from her expanding belly throwing off her balance, and Jen's hand gripped another corner of the shower for support.

When Ady's climax finally ended, he was left panting for breath, leaning against the back wall of the shower. Cum was dripping down her inner thighs and along the front of his balls from all that had escaped from her, and yet she still looked like she could be her own beanbag chair from how huge her belly had been swollen out. Both Ady and the two-headed fox simply remained where they were and panted heavily, needing time to recover after all of that, with only their breaths and the occasional drip of cum onto the floor breaking the quiet.

"Hey Ady," Jen eventually addressed him, "Can you turn the shower on?"

"Yeah," he agreed, fumbling for the controls behind him. One thing was certain, he was definitely going to come back to this gym again...