[Genderswap, Transformation, Cum Inflation]

Humanity and Monsters. Two races that seemed so different, and yet peace had been brokered between them so long ago that seeing them together wouldn't even make anybody raise their eyebrows. It didn't matter if they were so physically different, their bonds were able to keep them together. And despite the physical differences, there were a lot of similarities when everything came down to it.

"Blaaaake! I got the drinks! You want 'em now or do I put 'em on cool?"

One of those Monsters that had come to grow nice and attached to the Humans that he lived with was Rory. To most, he looked like an ordinary young lad. Brown hair, simple taste in clothes, with the only thing that really seemed to be off being his irises. But if you were to stick around him for a bit longer, you'd quickly see his tastes differ from his peers, and the way that he very clearly acted more like a humanized beast. Not that you would say it to his face, or really think it was a bad thing. That's just how Monsters were.

Rory put down a few dozen cans of different kinds of soda as he didn't get an answer to his question. Weird, Blake was never the type to be late with something like that. It was enough to make the young Monster scratch his head a bit. "You okay, Blake? Need me to grab the hose or somethin-"

*UUUUUUUUUURP*

Ahhh. Okay, that explained it. The loud burp that made the entire house shake due to the strength of those vibrations could only belong to one man, and it just gave him all the context that he needed. Right, he had to put away the cans later, right now he had to find out why his buddy was stuffed full to the point where he was burping that loudly...

The brown-haired youth strutted into the living room, and immediately laid his eyes upon his good friend Blake. A man that looked a few years older than he was, while having aged nowhere near as gracefully as Rory had. For one, the fat frame that was almost always decorated with some sort of nerdy merch really contrasted the much slimmer and much more conventionally attractive boy. Combine that with his glasses and the fact he didn't seem to have any shame when he showed off his much heavier body, and one would be hard pressed to assume that the two of them were friends if one saw them together on the street.

But that was how Blake normally looked. The black-haired nerd was not dressed in his usual digs. Instead, he was wearing a cozy black pair of pajamas that were definitely trying their best to keep his body nice and soft while his stomach just pushed out like he had been pregnant with triplets for way too long. In reality, the way that his belly bulged in such a taut manner meant that he was just stuffed. Though knowing their relationship, he probably wouldn’t mind being pregnant.

"Aaahhh... God, getting that out of my system felt real good..." Blake said, only to notice the grinning boy standing precariously close to his belly. "Oh, there you are, Rory. Sorry about that, I wanted to try and break a speed record. Crammin' as much food as I could manage down into my gut in the shortest time possible! I think I broke my record, but I dunno... I think I might try it again next week, just to make sure."

Rory chuckled as he grabbed ahold of that overly stuffed belly, grabbing a hold of a few of the buttons and popping them one by one to let the massive mound free, letting that plush mound really brush up against him. Which also helped bring emphasis to his big and almost cavern-like navel peeking out at the boy, which was just begging to be stuffed. "Well, congratulations on beating your record, big guy. You mind if I stuff another hole, or do you think you can't have any more of that good stuff sloshing around in there?"

"Stuff another ho-" Blake asked, only to let out a sudden and surprised moan as he felt something long and thick shove right into his navel. How was it this sensitive? And more importantly, why did... Ah, what the hell, it wasn't like it was actually a bad sensation or anything. All that he could do was chuckle a little as he leaned back on the couch, all while looking down at his friend. "You're a real tricky guy, you know that, Rory?"

"Wouldn't be your friend if I wasn't." Rory grinned as he teased his big and overly stuffed friend back, all while straddling that oversized belly. All while pumping his hips forward a bit to make sure that his cock was nestled as deeply inside of that hole as it possibly could. It felt way too good to do something like this. Honestly, he had fantasized about doing something like this for a long time. He just hadn't had the opportunity because Blake never ate too much.

Blake bit into his plump lip as his buddy kept on thrusting into his hole. In and out, in and out. He had never dreamed of how good this could feel. Sure, he had let Rory play with his holes a bit, especially when they were a bit too horny. But this was something else. This was an experience that would be very hard to forget anything about. Especially as that cock just kept on ramming harder and harder..!

Both friends let out a powerful moan, their climaxes intertwined as they both collapsed. Blake against the couch, and Rory against the pillowy belly that he stuffed full of cum. All while seed started to drool out around them. Both from Blake's crotch, and the gaps between Rory's cock and his navel...

"Haaaahhh... Your belly felt reaaaal nice, Blake... Mind if I do that again..?" Rory said, grinning from ear to ear as his cock immediately grew hard within that tight and plush hole that he had already lubed up with all his cum.

Blake just laughed a little in response. All while pressing his belly up against his friend. "Cum as much as you'd like, as long as you fix the mess after you're done." He chimed, knowing what the boy was able to do when he actually put his powers to good use.

Both chuckled and moaned as they decided to have fun for the rest of the day, using nothing but that big pillowy belly and the hole in the middle...

---

The day after, everything seemed back to normal. Rory had kept his promise, and Blake could fit right back into his usual outfit. Not that he bothered to try and put it on, walking around in trousers inside his own home as he planned to have a more relaxing day than before. After all, you get real tired after a whole day of nothing but eating and having your belly fucked senseless...

"Oh, Blaaaaaaake." And yet he wasn't going to get that. As soon as Blake found his way onto the couch, which was still a little squishy after yesterday's antics, he saw Rory pop out from behind the couch. The fact that the Monster had been hiding behind his couch wasn't bad, far from it. No, the thing that gave Blake pause was the bike pump and matching hose that he held in his hands, which caused the nerdy man to feel a bit of sweat pouring down his face. "Mind if I try something with that big belly of yours? It won't hurt, promise."

"Hmmm... Weren't you satisfied by fucking my belly yesterday, or what?" Blake asked, narrowing his eyes a bit as the glare from his glasses hid his displeasure. "What makes this so differen-"

He didn't get the chance to finish his words before that hose made its way into his mouth, and Rory's grin just started to widen with glee. "Relaaaax. I'll fix you back up just like before. I just wanted to try and see what it'd be like if I filled you up with air, instead of letting you stuff yourself! Besides, you were the one that seduced me with your belly yesterday, it's only fair that you give me the chance to pay you back." His argument wasn't exactly great, but he didn't plan on it to be very complex. Not when he had a magic pump that he could just keep pumping until his friend was as big as he needed to be.

Blake would've sighed if his mouth wasn't currently stuffed full, though not because he was frustrated. He just should've seen this coming. Ah well, it's not like being filled with air was going to be a problem or anything. He'd just end up a little more stretched and his belly was going to be more like it was genuinely pregnant, or something along those lines. So he just gave his buddy a thumbs up, and waited a little bit...

Only to quickly discover that what he had signed up for was maybe a little more than what he could handle. Especially as his boxers stretched out and snapped within seconds of his body inflating and growing nice and round. He grew bigger and rounder within mere moments, all thanks to the sheer amount of air that was being pumped into him.

"Whoaaaa. You've only taken in a bit of air, and you're already that huge!" Rory laughed as he just kept on pumping the bike pump he was gripping tightly onto. Pushing it in and out as he pumped more and more air into his buddy. Watching him grow and grow, all while his own pants grew nice and tight at the sight of the inflation taking place in front of his very eyes. God, it was so nice. He wanted to stuff his cock straight into his over-encumbered buddy already, but he had to make sure that he was as big as he could possibly get before he'd stop.

The more that Blake got inflated, the harder it was to think. Mostly because it felt like his mind was inflating too, and that meant that his thoughts were bouncing all over the place. It was getting harder and harder to do much of anything besides just accept the air flowing into him. And it wasn't just because his torso was getting nice and round and smooth...

It was also because his limbs had practically sunk into his body. Leaving him with nothing more than his head, his feet, his hands, and the rest of that enormous body that was now precariously balancing on the couch while the rest of his body was threatening to rub up against something and possibly pop if too much pressure was put onto it.

And when he was so big that he could barely fit into the living room, the hose in the front of his mouth popped out. The air wouldn't leave his body, all thanks to the magical nature of the pump inside him. No matter what hole was open, there was absolutely no air rushing out.

Which was exactly what Rory had been waiting for, as he grabbed ahold of his buddy and slammed his cock straight into the hole that was near the bottom of the inflated man's form. While he could dig his fingers into that overly inflated form, it was nowhere near as nice to fondle or play with as a proper pair of cheeks. But it would do for the sake of this little experience.

Rory and Blake both let out a moan as Rory once again slammed his cock into a hole that was meant for his cock, all while the oversized balloon of a man trembled all over. It felt so good to get fucked like this, like he couldn't even believe. It definitely didn't help that he had gotten used to Rory's cock over the time they spent together, which just made this slight change in the experience resonate so much more with him...

As for Rory? Well of course he was enjoying the sensation of this wonderful hole squeezing down on his cock. It was something that he couldn't ever have dreamed of. It was almost rubbery, yet it was still as tight and as wonderful as usual. Which just made him thrust his cock as deep inside as it could possibly go...

Right before they both let out a mutual cry like before, and Rory flooded the insides of the oversized balloon with a nice dollop of thick and white cum. All while panting and gasping as he held onto his friend for dear life. And yet the longer he held on for, the more his cock started to throb despite just letting all of that cum out into him...

So much so that he couldn't stop himself from indulging in a second round. Then a third, and then so much more until the balloon was just as stuffed with cum as it was with air...

This relationship of theirs always ended in pure passion, which was why Blake was more than happy to accept that his hole was being stuffed full again and again.

And even as he was kept overly inflated, a few thoughts on how their relationship could progress took shape inside of his overly stretched mind...

---

"Yeah, I can change you into a girl. Why'd you want that though? You're perfect the way you are."

It had been a few days since Blake got his ass turned into a balloon thanks to Rory inflating him with only the minimum required consent, and now he was the one on the offense. All while Rory was sipping from one of the many cans that he had bought earlier in the week.

"'cuz I wanna try it." Blake replied with a very casual tone, all while cracking open a cold one of his own. "You know, big tits, fat ass, all the good stuff. I've got some of that, so why not try and see what it'd be like on a female body?" He explained, gesturing to his general plump form. He should be ashamed of something like this, but being with Rory for so long allowed him to see the positives.

Rory tapped his chin before nodding. "Gimme a few." He said as he got off the couch and scampered into the kitchen, with comical sounds of tools and bowls and all sorts of kitchenware being tossed around echoing from the room. All while Blake just indulged himself and continued to drink the nice soda that he had been hankering for.

After being fucked by Rory for several days, each centered around a different kink, it was nice to just sit down and drink.

But it wouldn't last long. After what felt like half an hour or so, Rory ran back into the living room and dropped a delicate looking cupcake onto the top of his buddy's belly, letting it rest there like a cute princess on top of her throne. "Dig in, and tell me what you think." He said with a grin, swaying his hips left and right in anticipation...

Blake looked at the cupcake with a slightly crooked eyebrow. Right before shrugging and digging in, basically chewing through it in one fell swoop, letting the sweet treat rush down his throat as he let Rory's magic do what it needed to. Not that he really understood how it worked or why it had to be condensed into the form of a cupcake, but-

His eyes widened as a powerful heat spread all the way through him. He gasped and panted as he writhed on the couch. It wasn't because he was in pain, far from it. The reason why it felt so intense was because it was like he was melting. It was... God, it felt really nice come to think of it. So much so that he kept moaning and moaning, all while his body shifted ever subtly.

Blake wasn't wrong when he said he had a fat ass, though that didn’t stop it from getting nice and soft compared to how firm it had been before. That made it perfect for squeezing into, but it wasn’t easy to focus on his ass while his breasts exploded outward, letting his chest end up almost as enormous as the tits on those girls he loved to watch. All while his shirt grew shorter thanks to the added cleavage, revealing his pudgy tummy...

The changes themselves came to a swift end as he felt a rush between his thighs, letting him scream out in delight as his voice quickly shifted to a feminine pitch. And once she collapsed against the couch and let her shirt ride up to the point where her massive melons were sticking out and pointing right at her friend, she really was a wonderful feminine specimen...

Rory's response to seeing how good Blake looked as a hot chick? Simple. He climbed onto her and squeezed his arms around her, digging his hands into her brand new plump posterior all while stuffing his head in between her tits and making sure that he gave them a nice rub and snuggle. "Mmmph, I knew you'd be great once I had started baking that cupcake, but this is even better than I expected!"

"S-speak for yourself, I'm the one that had the idea in the first place." Blake shot back with a bit of an aroused tinge to her voice, all while trembling as she held him in her arms. As aroused as she was, this was more than enough for her. "Why'd you want to feed me a cupcake to transform me anyway?"

"'cuz I like seeing you eat." Rory said, before thoroughly motorboating those puppies to make sure that they were broken in. "But you're happy, right? I did good, right?" He was like a puppy whenever he actually did his buddy a favor. Looking for approval, even though it was obvious that she was satisfied.

Blake just chuckled and snuggled him a little more. "Mmhm. You really did, Rory. You really did." She whispered into his ear, all while cuddling him and making sure that he wouldn't escape...

She'd leave all the fun to later tonight, right now she just wanted to praise him and play with him a little...

---

Rory yawned. It had been a long day. Not only had he made that nice cupcake for his buddy, but he had to do a lot of shopping because Blake didn't want to show herself in public yet. Not that it was too difficult, but it just left him sore. And even though she gave him a lot of kisses, that would still tire anybody out. Which was why he was heading downstairs for a quick late night snack...

Right until the moment that he noticed that Blake was still sitting on the couch. Wearing nothing except for her pajama top, which wasn't even fully buttoned. There was so much cleavage that there was no way that she could properly close it up...

"You're still like this?" Rory asked, all while walking towards the couch and not even trying to avoid staring at the nipples almost poking out from that cleavage. How could he stop himself when he knew that she would be fine with him staring?

"Of course. You'd have to bake me another cupcake or something before I turn back." Blake snickered, before squeezing her tits into those massive tits. "Maybe I ended up a bit too big though. I could get my top on, but it really didn't wanna close. And I don't wanna think about ripping my pajama pants, they're too precious to me. Just my luck too, it's going to be real cold soon..."

Rory chuckled a bit back, though the fact that his buddy would end up being cold made a tinge of sympathy echo through his heart. "What if I cuddled up to you in bed, Blake? That'd keep you nice and warm, wouldn't it?" He asked, as he looked straight into her eyes. Instead of her tits or her pussy because for once he could concentrate and focus on his friend's needs instead of his raging hardon.

"Aw, that's really sweet of you, Rory. You never really ask. Maybe I've got more feminine charm than I thought." Blake laughed, before stretching a bit and getting up from the couch as she reached to grab the boy. "Then let's not waste any time. We've got a bed to warm up."

Blake demonstrated that despite her plump frame, she was rather fast. Because all that Rory had to do was blink, and then he found himself not only laying in bed, but with his head pressed in between a very lovely pair of pillows that were almost made for him and him alone. Especially after the covers were pulled over them and the warmth of everything started to wrap around them...

And since she was nice enough to stuff him right in between her massive tits, he felt that it only made sense for him to return the favor. Which was why he was currently grabbing ahold of her fat ass and fondling it as much as he possibly could. It really was beyond compare. Even Blake's old man-ass couldn't compare, and that thing was strong enough to endure getting clapped over and over thanks to how much he loved to fuck the man.

Rory couldn't stop himself from getting hard thanks to a mixture of the smell around him, the sheer softness of the ass he was playing with, and the nice sensation of all that tit flesh pushing against his face. He just kept on fondling and fondling. Playing away with it all until he could feel himself getting way too close to cumming. Not that he was actually going to orgasm without stuffing his cock into a hole, there was no way-

His eyes suddenly shot open as he felt a delicate hand stroke away at his cock. Not just softly or gently. No, this hand was very fast and furious, letting those fingertips really go to town as they went back and forth, caressing every little intricate part of his cock. Vein, shaft or otherwise.

A simple look upward would reveal the lewd grin on Blake's face. Of course she was behind that. There was nobody else that could play with his cock like this. And yet just staring into her eyes made him almost feel like putty in her hands. Ah, maybe he should just lean a bit more into it...

"That's it. Just relax and let me handle all of it. You've done such a good job playing with me for the last while, Rory. Now it's my turn to make you feel good." Blake grinned as she made sure to press him all sorts of close to her body, while his cock was pressed right up against her thigh where she could easily stroke it and make it feel all sorts of wonderful...

It eventually got to the point where Rory, who was able to endure stuff like this in the past, just couldn't. There was too much woman in front of him, and she was way too good at putting her curves and her body to good use. Which just resulted in him cumming under the covers. All while he grew nice and warm in between her tits, panting and gasping as his cock grew ever slightly limp after cumming and filling up the bed with his sticky gunk.

Not that he was allowed to stay soft for long. Not while she had him where she wanted him. She just giggled and stroked him off a little more, and he was right back to being as hard as he possibly could be. And for once, Rory was the one that had to worry about how long the two could keep going.

Because the look on Blake's face easily told him that she wanted to have lots and lots of fun...

---

The water poured down around Rory as he stood in the shower. It felt really nice for all that warm water to just pour down on him. All because of what had happened the night before. Not that he hadn't enjoyed it, but he was definitely just beyond exhausted. What else would you be if you had been forced to cum thanks to a fat-tittied buddy who was as thirsty as you were?

At least he thought that he could have a bit of peace inside of that shower. But not for long. In a moment of weakness, he closed his eyes... And when he opened them again, he had a fat pair of tits pressing up against him. "Looks like you're trying to wash off, mind if I help a bit?" Blake's voice rang out, all while a simple look up revealed that horny grin...

Rory returned the grin with a grin of his own. "Only if you let me play with these." He said, grabbing ahold of her fat udders and yanking her down onto her knees in the process. Mostly because she didn't even try to resist. If anything, she was happy to have him play with her like this. Even as he forced his cock in between them, going beyond merely playing with them and straight into fucking her tits.

Something about seeing that cock right in front of her face was making things click inside of Blake's mind. She could feel her pussy drooling as she panted and gasped, inhaling that virile scent. She wanted him to do much more than just fuck her at this point. And that feeling only grew more potent as she watched it thrust back and forward, grinding against her tits and making her arousal rise and rise further and further...

"Your tits are just perfect, Blake..!" Rory cried out, though it wouldn't take long for that titfuck to bring him to a climax. Forcing his seed to shoot straight into the air, before it came crashing down on his partner's face thanks to the shower pouring all the water down on them. Leaving her only temporarily glazed with all that sticky white goodness before it naturally got rinsed off her...

Blake panted and gasped as the cum poured down her body. All while she slowly forced herself back up. God, it felt so good. Her nethers were throbbing, her heart was pounding, and she couldn't stop herself from pressing up against the glass that kept them separated from the rest of the bathroom. "Fuck me, Rory. Fuck me long and hard and knock me up and make sure that I get filled way more than you've ever filled me..!"

"I was planning on it!" Rory cried out, laughing as he grabbed onto her hips and mounted her while slamming his cock into her overly soaked pussy. She wasn't the only one that was pushed to her limits, he had been harboring the same feelings. All because of how dominant she had turned when she became a girl. And while he had fucked her ass plenty before, breaking in her pussy would be a treat.

Both of them let out soft moans as Rory's initial thrusts weren't very impressive. They were soft and tender, though the sheer size of his girth meant that she was already being bulged out to the point where it looked like a horse had stuffed its member into her, and forcibly stretched her womb.

Not that it was a bother for her that she was bulging like this. It was a show of their love. It was a show of how wonderful it felt to be friends with him. It was something that she had come to adore, even before she became like this. Maybe it was why she had asked to be turned into a girl, and she had only now realized it. Whatever the case was, it felt good to have him stretch out her womb..!

Both of them just kept on moaning as Rory thrust harder and harder, stretching her further and further and further until it felt like he was ramming his cock up against the glass in the same motion. He was bulging her way more than he was meant to, and yet that was just part of the fun of it all. But once he had gone that far, he knew that he couldn't hold it back any longer. He pulled his hips back and looked into her eyes, just barely as she looked over her shoulder to meet his gaze...

And then Rory slammed with all of his might. Letting out an almost primal scream of pleasure that was quickly met by Blake's, the two let their cries echo out as the passion between them reached a whole new peak. All while a flood of cum poured out from Rory's cock and straight into the fertile womb inside of Blake.

Gallon upon gallon of cum poured inside, quickly making the overly stuffed belly fill more and more of that space. Leaving very little room for either of them to move, as the sounds of the water pouring out above them were drowned out by the density that the sound of cum pouring into that hole made.

And by the time that he felt like he had been filling her enough and that his cock needed to rest, he tried to pull out. But Rory found that he couldn't. In fact, as the rush of cumming started to die down, he was quick to realize that he was stuck up against the wall because she had simply grown too much. Even she couldn't move, her belly keeping them both pinned up against the back of the shower...

"Guess we're stuck here." Rory said, not that bothered. Especially not as his cock started throbbing. He was still stuffed into the best hole that he had ever fucked, after all. "Round two?"

Blake licked her lips a little while her hole tightened. "I thought you weren't going to ask." She chimed, not at all bothered by what might happen if they fucked again.

Even after all of this, their relationship was as passionate as ever. The only change was the possible dangers of cumming inside Blake too much. A danger that they both ignored, more than ready for the consequences.

That was the life of a horny Human and an equally horny Monster. Locked in passion to the point of procreation, just like the ones that had brokered peace between their races in the first place.

All while their moans started back up, and round two began...