Too bad the story never continumed

Enchanted / Magic diaper might work here.

@Registered Anon  
According to the story, the second one is enchanted. Besides, the more padding, the merrier.

Why two diapers? Is the second one to catch leaks from the first one?

The fun has been doubled :3

When you’re so constipated you doodle a summoning circle on your diaper so you can perform a ritual that will draw the poop out of you. Unconventional but possibly effective.

don’t talk back to me I’m george rackham son of the fourth Earl of windsor

@Background Pony #5D6A  
There’s a “diaper fetish” tag you can filter if you don’t like it, instead of whining about it, dumbass.

“Spike… are you sure about this?” Rarity said, antsily, her marshmallow white hooves making cute little clopping noises on the laminated floor of her main downstairs room as the little purple dragon fished through the backpack he’d brought with him, taking out a pacifier here, or a bonnet there, while his erstwhile white pony fidgeted in place, “This all seems to be going rather fast for my tastes, and I’m not quite sure if I-”
 
With a motion more efficient than fast, Spike picked out a bright purple pacifier from the things he’d brought, and stuffed it into the white pony’s muzzle, enjoying the look of shock, then embarrassed outrage that shot across Rarity’s face as she looked down at him, entirely bereft of words, her cheeks reddening. “Hush, little filly,” Spike said, with a grin, and a giggle, and patted her velvety soft cheeks with one hand… before dropping a massive diaper flatly on the ground in front of her, leaving Rarity to gawk down at him even more than before.
 
“Thpike, ahm arrewdy weawing one off thoth,” Rarity said, unconsciously trying to talk around the pacifier, and making herself sound like a foal in the process, which made Spike break out into giggles. The white pony was, indeed, already thickly diapered… but was she thickly diapered Enough? Definitely, definitely not.
 
“Lay down, my precious little baby gem,” Spike cooed, in the sugary voice he’d already been conditioning the white pony to get all wiggly when he used, and it didn’t fail him now! Rarity whined, but did as she’d been told… partially, no doubt, because she’d finally looked down at the diaper he’d picked, and been oddly captivated by the purple symbols it had in place of a default print! Spike wasted no time in getting to work, lifting Rarity’s rump up by one hind hoof, which he was finally big enough to do, and sliding the extra thick padding underneath the already considerable first layer. As it started brushing against her velvety thighs, the purple marks very slowly took on a soft purple glow, exactly as the instructions had informed him they would, and Rarity started looking increasingly more confused. The considerable padding was flipped up against her tummy, and then, with finality, taped in place with two enormous tapes. Even Spike, who was still young for a dragon, and had relatively little understanding of unicorn magic… except of course what he’d picked up from a lifetime of being assistant to Twilight Sparkle, of course… could feel the diaper vibrating with power. He’d bought them out of a newspaper, off a unicorn in Canterlot, of all the silly places, and had them shipped. Whoever he was, that unicorn must have been something of a powerhouse. Even most of Twilight’s enchantments didn’t vibrate like these things!
 
“Whaahh…?” Rarity said, her eyes slightly glazed over as the three enchantments on the diaper took over. One to grant the designated ‘parent’ a nearly hypnotic ability to command the wearer, one to prevent the diaper from being removed by anyone but the same designated parent, and one to completely revoke the wearer’s control over most of their body, making them think, and feel, like a clumsy, foggy headed foal, once again, with just enough adult cognition left over to feel embarrassed. Spike wouldn’t have had it any other way.
 
“Who’s my pretty little girl?” Spike cooed, and watched in clear satisfaction as the pony he’d crushed on since his first day in Ponyville wiggled around on the changing mat, and made some incoherent babbling noises as she tried to roll over and sit up, but could only do so clumsily… This was going to be quite the fun night! Possibly… the MOST fun night! Twilight is out to dinner with her brother, who’s in town, and hadn’t left him any chores to do…
 
“Spike…!?” Came a voice that shocked the purple dragon practically out of his scales. With Rarity still googly eyed and giggling as she wiggled her thick diapers around, and eyed him like he was the most important dragon in the world, Spike glanced up… to see an entirely different unicorn staring slackjawed at him through the window next to the side door of Carousel Boutique…
 
…“So that’s how that feels…” Spike groaned.
 

 

 
 
Continued from http://www.furaffinity.net/view/30590116/
 
You done goofed, Spike. You done goofed… Now EVERYONE is going to know you like turning Rarity into a baby! Just tell her she has a fetish for public embarrassment, or something. To be Continued!
 
360 Minutes  
Manga Studio 5x  
February 2019
 
Adamant Artist Challenge #490
 
Thanks again!  
~Kodikins