Keith had a problem. Perhaps you could call it an addiction. Ever since he was young hyena pup, he’d been jealous of his cousin Rob’s diapers. The pair of cousins were raised practically as siblings since they’d been born around the same time, but Keith had graduated from his potty training relatively early whereas Rob had been kept in them.
	
	It didn’t make sense to him when they were pups and Keith would often steal a pair of Rob’s diapers to put on. When they young, their parents thought it was cute that they wanted to match, but as he got older it became discouraged. But with that age also came the understanding that Rob wasn’t a normal kid. And neither was he.

	Rob didn’t seem to mature as fast as others. When it came to diapers, that maturity never came. The boy seemed completely incapable of making it to the bathroom on time. To make matters worse, the hyena also didn’t seem to understand social cues and once he learned that it felt good to rub his diapers when they were wet, he made it a regular activity until his parents began locking him up in a hard locking rubber cover that prevented him from touching himself. 

	For Keith, it had been a humiliating secret that the chastity device and learning of the boy’s inability to touch himself had only furthered his curiosity and desire to trade places. On more than one occasion, Keith had secretly tried on the diapers, learning how good it felt to hump and paw at them as he’d seen his cousin do. It was actually his first time ever cumming at all. 

	Practically neighbors, he had plenty of opportunities to steal and use diapers in the night. But that had also led Rob’s parents to inevitably discover them, believing that Rob was somehow taking off his chastity device in the night which led to them also putting him in locking mittens that restricted his movement and a muzzle that would prevent him from biting at his restraints in the night. Surprise, surprise – Keith only grew more infatuated. 

	The teen began getting more smart about his theft. It had been borne of desperation, but he’d taken used diapers from the pail for his naughty fun and found that he rather liked it more than using them himself. But it also led him to realize that it wasn’t just the diapers he liked. He loved the thought of swapping places with his cousin. To be kept in Rob’s diapers and forced to use them. To be kept in chastity to prevent him from being a big kid. And the thought of being trapped that way forever.

	It was a fantasy that he often visited whenever he pawed himself off in his cousin’s diapers and one that he secretly hoped would somehow happen. But one day, he realized it wasn’t like he couldn’t try getting away with it. They were cousins. They were similar in height and fur pattern minus a few spots here or there...nothing that some dye couldn’t fix. They were still friends despite their mental differences and while Keith had never admitted why, he had hinted to his cousin that it’d be fun to do a prank on their parents like that which the boy had agreed would be a fun idea. 

	And so Keith started testing the waters. He began making plans with his cousin. Hiding away a stash of diapers at his house. Making sure his cousin knew where the keys to the chastity device was kept so that he could inevitably be let out. And it all seemed to be going to plan. Then came the promised day. 

	Rob giggled as he put on Keith’s clothes over one of his thinner discrete diapers. Keith normally wore very baggy clothing that did well to hide the bulk of the protection. “This is gonna be fun,” Rob cackled, looking at himself in the mirror. “Look, it’s me, Keith!” he mused, pointing to the hairstyle change they’d done and the dyed spots. It wasn’t a perfect job, but most of the obvious indicators were hidden. 
	
	Meanwhile, Keith had rather embarrassingly strapped on the warm diaper that Rob had just been wearing moments prior to his change. One of the more embarrassing parts of their friendship had been that Keith had been letting Rob out of his chastity cover whenever his parents weren’t around and helping him get off by rubbing at his diaper front. Today was no exception, and he felt the sticky results amongst the squish of his diaper as he’d put it on. This was the first time he’d been in a wet diaper around Rob and wasn’t sure how his cousin would react but he mostly seemed unphased.

	Horny and abashed, he began rubbing the front of the diaper, moaning as felt the warm plastic rub against his privates and start to cloud his thoughts. 

	“Ahh ahh ahh,” Rob said as his eyes drew to the commotion. “Baby hyenas don’t do that,” Rob chastised him, grabbing his paws and pulling them to the side. 

	Keith blushed. “Rob...I just helped you do this. We’re the same age.”

	Rob shook his head. “Uh-uh. Bad babies get put in their special undies.”

	“But- I-” Keith whimpered. This was part of his fantasy after all. Should he play along? Surely Rob wouldn’t do him like that, right?

	Still very much horny and not thinking straight, Keith allowed Rob to put him in the locking rubber cover...and then the mittens…and the muzzle. He whined without volume and humped uselessly at the rubber cover but while his penis felt so good to be in the wet diaper, he could generate no friction. He had no idea it would be like this. And his body was edged at the verge of bliss, unable to tip over. 

	Rob then picked him up and put him into the railed bed he slept in every night and lifted him in, sliding the rail up. “Good. You’re in time out. Think about what you did,” Rob said, lightly bopping him on the nose before disappearing. 

	Keith whined, stuck on the verge of cumming. How was he so horny just from this? Surely Rob would led him out before too long and he could secretly cum in private, right?

	But Rob didn’t come. An hour passed. Then a second. All the while Keith knew that Rob’s parents would be back soon. In a fit of desperation, he tried humping the pillows, the rails of the bed, his mittened paws, but all he did was edge himself closer. He only had one option left – to make his diaper more wet in hopes that it would do enough. After positioning himself and pretending that he was in front of the toilet, he began to piss himself, feeling the diaper expand to the limits. It was already mostly full when he’d put it on. The edges of the cover began to leak. But he didn’t have time to wait for it to soak in. 

	Humiliatingly, he began to hump the leaking diaper against the pillow, feeling the piss splash down his legs as it was forced out from the legguards. But it was working. He could feel the slightest bit of friction as his diaper tent made contact with the exterior cover and the soggy padding gave him just what he needed. Moaning louder than he ever had into the muzzle, he blew his exhausted load into his diaper, panting heavily from the sheer sudden exertion. 
	
	He came to his senses just in time to realize that the commotion had drawn company. Except it wasn’t Rob. It was his father. And he was shaking his head. 

___________________________

	The swap had been a success. At no point had Rob’s parents seemed to notice that he was actually their nephew. The problem was that in the afterglow of his orgasm he’d started to have second thoughts. Especially once he was caught red-handed cumming in his diaper they’d affixed an actual cage to his cock – one that he didn’t even know that they owned. And while it was a fun thought, he now realized that the prospects of actually enjoying his situation were even slimmer than before. 

	But all he had to do was hold out until Rob came back. Then they could swap back. 

	For now, he chagrined as he’d been put in front of a pile of blocks. The only thing he could realistically play with mittened paws and the supposed intellect that Rob possessed. He sighed, picking up one of the blocks between his paws. He’d need to make the best of it. 

___________________________

	It had been a week. Rob should’ve been back by now. At this point, the cage was starting to strain from how horny he got whenever he pissed himself or whenever his aunt or uncle would change him.

	On a plus side, he’d found more fun things to do with the blocks than just stack them. It turns out that he rather liked building. Still, he’d prefer his video games, his cell phone, and hanging out with his friends. The baby tapes and building blocks and kids shows really were fun and scratched some strange itches inside of him, but not for long, he hoped.

___________________________

	It had been a month. It was bad. He was starting to have real accidents at night because he wasn’t allowed to do anything other than pee his diapers. Worse yet, Rob’s parents weren’t willing to let him try potty training on account of their busy schedules. But they’d get a babysitter for him and then he could try. 

	That babysitter? His little brother, Alex. The punk realized immediately what had been going on because Rob had told him the situation. Apparently the ten-year-old had been snagging diapers to help his cousin potty train in secret so that he could make the situation permanent and Rob had agreed. 

	It was starting to get to the point that Keith was ready to fess up and take the punishment that came with it. But Alex wouldn’t make it so easy. The fur pattern which had begun fading was touched back up with new dye and the punk had gotten really good at “putting Rob down for the night” and then showing up the next morning for babysitting duty. It afforded him no opportunity to be alone with his aunt and uncle. It would still only be a matter of time before classes would start up and then Alex wouldn’t be able to keep this up, or so he thought. 
	
	Nepeta Crocuta. Essentially catnip for hyenas. Not only did it make hyenas extremely giddy. It also made them dumb as a rock. In large doses, it prolonged its effects and could last for days...or weeks when abused. And when it was fed in from a forced baby bottle, he didn’t even know why he was suddenly so confused until it was too late.

	Before long, Keith felt about as dumb as a toddler. His words were difficult and the kids shows and toys began distracting him. From his punishments. From his accidents. From his identity. 
_____________________________

	School had come back around several months ago and Alex only visited every few weeks to “babysit,” but he quickly learned that Keith had really taken on the role he so desperately wanted. There was no need to redose him. As for his fur pattern, he’d been sure to slowly make little changes over time until the original color was forgotten. They tended to change in growing boys anyway. 

	“Hey Keith,” Alex asked just loudly enough for his older brother to hear him. 

	There was no response as the restrained teen fiddled with his blocks. 

	“Hey Keith,” he repeated.

	Once again, the older hyena stacked another brick.

	“Hey Rob,” he called.

	“Uh-huh?” Keith said, tilting his head dumbly back to greet his ‘big cousin sitter.’

	Alex snickered. “Want me to show you something really fun?”

	Keith tilted his head once more, not understanding anything other than the word fun, so he nodded his head. 

	Alex had prepared the keys ahead of time. One by one the restraints came off until the older boy was sitting there in nothing but his soaked diaper. Then Alex dropped the front of his brother’s diaper, slipping the key into the chastity cage before pulling the diaper back up. Alex gave the soggy crotch a playful squeeze to jumpstart the confused hyena. 

	Like a spark to a flame, Keith’s paw went to his crotch and began humping wildly. Within seconds, the older boy spasmed into his diaper, letting out a loud moan and kept humping his paw and his bricks and everything else he could find. 

	As if the orgasmed had imparted the slightest bit of lucidity back to him, he looked to his brother and said “thank you.”

	Alex smiled and sat next to him, patting his diapered rump which was flagged up into the air enticingly. “Don’t thank me yet,” the boy said, dropping down the back of his older brother’s diaper and lowering his pants. He positioned his penis at Keith’s hole and pressed his six inches until he was leaned up against the larger hyena. He whispered into his ear “now.”

	Keith whined in ecstasy as he felt his penis spark back to life. “T-thank you.”

	The younger boy grinned toothily and bit down on his older brother’s nape. This was going to be a fun job.