The door opens to reveal Uncle Jack and your ears perk up as you sit up like a dog, and felt the warm contents in your diaper smoosh up against your ass sending your mind into a euphoric ecstatic haze. You took a deep breath and felt your bladder release itself and stain your diaper yellow as Uncle Jack looked over your large furry canine body before grinning. "Well now, this is unexpected, must've found that old mirror back here while nosing around weren't ya boy?" He asked, and while your mind was devoid of human intelligence you gave a small nod like the obedient good boy you were.
This made Uncle Jack smile and laugh, and he reached down and began scratching you behind the ears and under the chin, both of which felt incredible and your leg started thumping against the floor while your tail wagged. "Heheh, I think I know just what I'm gonna do for ya Johnny boy," He added before a bright red collar with your name on it appeared in his hand, and curious you began sniffing it before he placed it around your neck.
The moment the collar was put around you, it started glowing and felt an incredible surge of pleasure throughout your body. Looking down you watched your muscles on your arms, legs, and chest swell and bulk up giving you the outright colossal muscle mass of a body builder. After this you cock and balls doubled.... no tripled in size, and peering down you saw the outline of your balls pressing against your diaper, and your erect shaft strained against the waistline of the diaper, begging for release. This made you whimper and squirm from how your diaper was squeezing your doghood, but it wouldn't end there since you felt your stomach gurgle giving you even less bowel and bladder control that you had before, and beneath your diaper your ass swelled up as well as your hips, bubbling up so that each cheek was about the size of a pumpkin. Your anus had a similar story with its puckered lips growing and bulging to form a large puckered up donut, making you capable of filling your diaper much faster and far more than ever.
However this also put a heavy strain on your current diaper and you whimpered worried that your precious diaper would burst apart, but then suddenly Uncle Jack clipped a leash to your collar and draped a blanket over the mirror. "Come on boy, let's get you outside to empty out what's left in ya them give ya a bath," Uncle Jack exclaimed and you nodded, walking to his side and willingly following Uncle Jack outside to the front of the shop.
Once you were outside Uncle Jack commanded you to lay on your back, and you did just that, laying back and exposing your stomach like any dog would. Uncle Jack would lean down and begin rubbing your belly, and prod at your cock through your diaper which made you whimper before yelping, your cock throbbing as it released its load, and panting afterwards. You then watched as Uncle Jack removed your diaper slowly which made you whimper, you felt proud to have a shit filled diaper around your waste 24/7 but felt vulnerable without it.
"There there boy, you'll get a much better one soon, now I order you to empty put everything you have in you, don't worry I'll clean it up later. After that I want you to show me your ass and balls boy, and let me see how much of a good boy you are without the diaper." He ordered and you nodded and sniffed around, before finding a nice bush first and lifting your leg, and releasing a large golden shower from your cock which was well around a foot and a half long now for about 30 seconds. Immediately following this you squat over and stare out and see all the passerbys watching you just before you release a volley of shit from your anus. After making a nice pile of fresh shit on the ground before you kicked some dirt over it to hide your scent a little before showing your ass to Uncle Jack. Before long Uncle Jack started hosing off your dirty shit covered rear end, and rinsing all of the left over contents from your diaper off.
For you this was surprising and made you yelp, and when he stopped you shook off and looked up at your Uncle while wagging your tail. "Good boy, now until you have a diaper on again don't you dare think about taking a piss or shit again, got it?" Uncle Jack commanded, which at first it was sorta disheartening, but then again what good was it being a proud obedient diaper dog and relieving yourself without having a diaper to catch it all so you could show it off to everyone? With that small bit of logic you perked up and followed Uncle Jack as he took you back inside the shop, and then guided you upstairs and into the bathtub.
"You are such a good boy, aren't you~?" Uncle Jack exclaimed after you sat down in the tub, petting your head and rubbing your cheeks before giving you a small hug, "I think you will fit in perfectly here, and thanks to that collar nobody will know the old you, just this you, not even your parents. Now wouldn't you like to be my adorable little diapered puppy for good~?"
In response to this you gave a small woof, and licked your Uncle's cheek affectionately which made him laugh and pat you on the head before he started the water. After this he started washing your furry body all over with soap and water, getting deep into your fur and skipping over nothing. You especially enjoyed it when your Uncle scrubbed your paws, tail, ass, anus, and crotch. Your crotch especially, your Uncle was very thorough when it came to your cock and balls, and your canine knot unsheathed as he caressed your doghood from your hefty testicles to its tip. Before you got out of the tub, your Uncle gave your balls a nice squeeze which made you yelp, and then orgasm and spray a nice amount of your seed into the water.
After this your Uncle had you get on out so he could dry you off. However the moment he grabbed the towel and began drying your paws, your instincts kicked in and you shook off on all fours and licked your Uncle's face, making water go everywhere and all over him too. Your Uncle paused then sighed and gave you a small pat on the head and chuckled,"I should've expected that out of you, now then come here."
You would nod once more and then you followed your Uncle into the kitchen where he snapped his fingers and produced a new diaper, this one looked much larger, much puffier and stretchier too. You got excited and jumped up to sniff it immediately before your Uncle ordered,"Down boy, on your back!" Then immediately you whined and laid down on your back once more and looked down, and watching your Uncle fasten on your fresh new diaper.
The new diaper felt so soft, so warm, and instead of straining your cock and balls, it comforted them with a pillow-like softness that cradled your hind end from all sides. You couldn't wait to empty your bowels into it, in fact you felt like you were going to any second. But then you saw Uncle Jack put down two large dog bowls, one full of water and the other full of kibble which made your ears perk up. It wasn't ten seconds from him putting them down that you weren't already sticking your face in your food bowl and chowing down like crazy, before taking a huge gulp of water once your doggy bowl was empty.
Your tail wagged as you felt your body doing its thing all over again, you felt the churning in your stomach and gurgling as you let out a nice wet fart. Then you squat over in front of Uncle Jack and as he watched you reached back with one hand and down with the other, rubbing your anus and also your cock before you let out another wet fart and barked as you grew nice and hard again.
"Heheh, go on and do it, you have a diaper on after all boy," Uncle Jack chuckled and without warning you released a new volley of shit into your diaper, feeling the clumps coming out as they exited your anus with one hand as you stroked your tented cock through your diaper, panting. You were in utter bliss, tail wagging as you filled your diaper as much as you could whilst stroking off, and you gave a small bark before howling as your orgasmed heavily into your diaper as it sagged and turned brown and clumpy with your excrements.
"Good boy," Uncle Jack said before petting you and getting out his own food for dinner, eating at the table and you crawled right up on under him, planting your head between his legs with the tip of your muzzle resting on his lap as you sat down in your messy diaper once more. You sniffed his crotch with your nose, part of you wondering what his cock looked like, but you quickly push those thoughts aside when he began petting your cheek and head again to show you that you were in fact a good obedient boy, and a loyal companion.
You were so proud to have Uncle Jack as your new master, he took such good care of you. You could already imagine sleeping at the foot of his bed, rolling over for belly rubs, playing fetch, tug-o-war and more with him. But what you found the most pleasurable were the thoughts of him taking your soggy diaper off, cleaning your ass, only to put a fresh diaper on for you to fill it up again. You were such a spoiled pooch, and you loved it, no more thinking, just pets, playing, sniffing, meeting new people, and taking some of the greatest, biggest shits of your life into a diaper.
After Uncle Jack was finished eating he allowed you to have whatever scraps he had left and lick the plate clean before taking you back down to the shop. You eagerly wandered around once more, sniffing before attempting to mark your territory on the carpet only for you to stain your diaper yellow, which was even better! Looks like you were the shop's new mascot, and you wandered around before Uncle Jack made a large comfy dog bed for you to curl up in, and behind the front desk no less. So you went on and curled up in it and watched Uncle Jack above you smile and pet you before...