Sunny awoke with a stretch, and felt something wet on her cheek. She slowly raised her face from her pillow, and discovered that she had been sleeping so soundly that she had been positively drooling. She pulled the covers off of her, and found that her wet diaper, while still swollen, wasn't warm anymore, but cool and clammy.

That might not be an issue much longer, due to her bladder itching to get its morning relief, as was the routine for most ponies getting up first thing in the morning. She swung her back legs over to the edge of the bed and hopped down to the floor. The first thing she noticed was that Izzy wasn't there, and looked at the clock on the nightstand. The alarm hadn't been set, so she had slept in until 8:30. Right in front of the alarm clock was a note. She walked up to the nightstand and read it.

Dear Sunny,

I made a quick trip out into town to get some more things for you. If you're reading this, I didn't quite make it back in time. Be sure to be a good little filly while I'm gone! I'll be back soon with more supplies. I'm sure your diaper will hold out until then.

See you soon!

-Izzy <3

Sunny smiled down at the note, figuring that Izzy was indeed planning on carrying this through to the next day. She could only guess that she was out getting more foal items. So for now, she went back over to the sink, and while she turned on the faucet to a trickle, she saw that the bathroom door was closed, and from the bottom of the door, didn't look like the light was on. Maybe it was just a subtle reminder from Izzy to remind her to not use the bathroom.

The trickling water once again did the trick, and on slowly letting out her next breath slowly, her bladder relaxed and let out a stream of urine out into the already wet padding. Already standing on tile in case of any leaks, Sunny was surprised at how it took it absorbed another complete wetting and swelled up even more. She started to wonder how much it could take before it either began to leak, or she would be unable to walk.

But at the very least, her diaper wasn't cold and uncomfortable anymore.

Shutting off the faucet, the absolutely soaked Sunny waddled back over to the bed, figuring she'd try and get more into a 'little' headspace by turning on the TV and watching some morning cartoons.

But just as she sat down and turned on the TV, her lower half gave her another call of nature, this one a little closer to her tail.

Now, for the first time, Sunny felt a shudder of nervousness. Wetting herself seemed easy and harmless enough, but... Pooping herself seemed considerably more taboo. Not wanting to commit herself to that just yet, she was hoping that Izzy wouldn't be mad if she broke this rule. She got back up, leaving the TV on, and walked back down to the bathroom. She reached for the door handle, and found that it did not move. At all.

'What?' Sunny wondered. She didn't think these hotel bathroom doors were supposed to lock from the outside.

She paced nervously for a few moments, until she heard the card reader on the front door click, and it swung open.

In came Izzy with two shopping bags in her magical grasp.

"Well, I was hoping to get back before you got up. What do you think you're doing back there, my little filly?" Izzy asked as she set down the bags on the table in the corner of the room.

Sunny felt like she just had her hoof caught in the cookie jar all of a sudden.

"I... You see, I was, uh... I need to... You know, go..." Sunny said, her cheeks tinting pink again.

"This is why I wanted to be here before you got up," Izzy said, walking towards Sunny in the back of the room. "To ease you into this stuff and keeping you comfortable for some of the bigger steps."

"This door isn't supposed to lock from the outside. How did you do that?"

"It's not too hard for my magic to do something as simple as turn the lock from the other side of the door, silly Sunny," Izzy said with a smile, guiding her back towards the beds.

"Izzy... I'm not sure if I'm ready for something like this..." Sunny confessed.

"Something like what?" Izzy asked.

"You know... I'm not ready to... To poop myself..." Sunny said, embarrassment washing over her again.

Izzy came to Sunny's side and put her front leg around her reassuringly.

"Oh, I think you might be more ready than you might think. Especially with me here. It's a big step for a new filly, but I know you can do it. I think you'll feel a lot better once you do."

Sunny shuddered again, nervous at the prospect of doing something so... Foalish and helpless, and yet, encouraged by her best friend's words.

"Come on, if you do this for your foalsitter, I'll have a treat for you after breakfast," Izzy told her, taking a step back and giving her best friend some space.

Sunny took another breath, and realized it wasn't going to be as simple as running a faucet this time. She spread her back legs, even more so than they already were with the swollen diaper around her waist, and took another breath, taking on a distant stare as she retreated into her mind and began to concentrate. She was in the bathroom, just barely above the toilet... Having barely made it in time...

Sufficiently in her headspace, her tail hitched up, and she instinctually pushed with the appropriate muscles. A moment later, the slimy mass started to exit her body, and immediately met the inside of her diaper. There was a resistance for just a moment before it gave way and began to spread out across the already soaked padding.

She let out a gasp. It was hot, almost too hot at first. But with the heat came an indescribable feeling of relief. After the first push, her muscles tightened and were ready for a second go. She clenched for just a moment, then pushed again, and the rest of her morning load came out.

When she was done, she came to the realization that she had been holding her breath, and let out a long, exasperated breath as heat once again built up in her face, along with the heat that was now being held against her nether region by the crinkly, swollen padding.

"Good job, my little filly. I'm so proud of you," Izzy said, coming forward again and wrapping her front legs around her friend. "What a stinky little foal I've got now."

Izzy led the padded earth pony over to her bed, and the unicorn laid down first, sitting up against the headboard, before magically lifting Sunny up and setting her down in between her back legs, snuggling her into her barrel. When her bottom hit the bed, her mess spread out even more than it had, and she shuddered again. She felt so little, so naughty. Big mares didn't fill their pants like that. She wondered if Sprout had felt the same way the first time he had to do the same.

"Alright, my little Sunny. Breakfast time," Izzy told her, her horn lighting up again, and she floated over the bottle of milk that she had prepared while Sunny was doing her stinky deed. By the time the bottle reached her lips, the stench had reached her nose, and she resisted the urge to tear up at what she had just done. But Izzy was right here, and she'd get her cleaned up when she was good and full. She opened her mouth, and the bottle's nipple entered her mouth, and she began to suckle. The bottle was considerably bigger than what you'd find a foal feeding from, and this was undoubtedly an adult-size serving of milk for breakfast.

Izzy gently wrapped her front hooves around Sunny, keeping her snuggled against her barrel, massaging her chest and stomach as she nursed from the bottle.

"My what a stinky filly..." She said playfully, her words reminding Sunny of her deed, along with the constant stench that was wafting up to their nostrils.

A couple minutes later, the bottle of milk was empty, and Sunny let out a hearty belch as the nipple was pulled from her lips.

"Alright, little Sunny. One last thing before I get you changed. I believe I promised you a treat after breakfast for using your diaper..." Izzy said.

Sunny was sufficiently intrigued by what Izzy had in mind when she made no move to get up from the bed or otherwise release her from this gentle, snuggling embrace. Instead, she saw her horn light up once more, and her saddlebags lit up, and a large, white cylinder came out of the left pocket. There were buttons on the bottom part of it, and at the top was a rubber white bulb. As the unicorn slowly levitated it towards Sunny's diaper, she saw the indicator light right above the top button turn green, then heard the bulb pulse and vibrate wildly a second before the unicorn magically pressed it against her soaked, smelly padding.

Sunny let out another gasp at what the unicorn was doing. She began to squirm, but her friend's hug tightened just enough to keep her securely in her grasp.

"Now, just relax, little Sunny. Let's make you extra sparkly," Izzy said, slowly moving the head of the vibrator up and down against the plastic surface of her well-used diaper.

Try as she might to stop her squirming, it was a lost cause, as she felt her marehood become wet, and not from her wet diaper.

"Here, this'll help..." Izzy said, pulling another item from one of the bags she had brought in; a pacifier that looked a lot bigger than a foal would need.

A small, regular foal, that is.

Izzy waited until Sunny's next gasp, and popped the large nipple into her mouth, pressing the large red shield against her lips.

"There we go, now you look the part even more, and it'll help you keep quiet," Izzy said, pressing the vibrator into the diaper even harder.

A half minute later, Sunny wasn't trying to squirm away from it, but was now pressing into it.

"That's it, little Sunny. I'm here to take care of all of your needs, and that includes the ones that big foals have. Now come on, let it out. Show me how much you enjoy your diapers."

This was a side of Izzy that Sunny had not seen before, and as her breathing quickened, she couldn't help but wonder if she had also done this with Sprout, which perhaps sped up his acceptance of this treatment, this fetish.

She guessed it probably worked on him, because honestly, it was working on her too. Being embraced by her best friend, being talked to like an infant, and also a full-grown pony who needed help getting off... All while sitting in her own urine and manure...

"Ah! Mommy!"

Sunny squealed into her pacifier, and her limbs stretched as far as they would go, as Izzy held her tighter.

"There we go... What a good girl, all sparkly again..." Izzy praised, removing the vibrator and replacing it with her own hoof, slowly bringing her down from her padded orgasm.

Sunny caught her breath as quietly as she could, and as she did, she knew she now wanted nothing more than to get out of this filthy diaper.

"And did I just hear what I think I did? Hm?" Izzy asked, as she continued to gently rub Sunny's swollen, smelly diaper as she pulled a fresh one from the pack.

"I... Uh... I'm sorry..." Sunny replied meekly.

"Oh, Sunny. Don't apologize. I'm flattered. Now..."

Izzy slid off the bed onto her hooves, letting Sunny fall back into a laying position as she got the fresh diaper unfolded.

"Let's get my stinky little filly changed."

Author's Note

Now we're talking, Sunny.

Thanks for reading so far, more to come!