Diapered Over Top

It was the morning of the third day. Applejack had already changed Rainbow Dash after her morning pee, and she was now sitting in a special kind of baby feeding chair that, once the table was locked in place, she couldn't get out of if she tried. At first she had struggled to get out of it, but had eventually given up on it. She was still allowed use of her hands, and to drink water, soda, or cider out of normal bottles, and eating normal food. Much of it was messy food that she would eat with her hands, getting some on herself.

Then, Sunset Shimmer, Twilight Sparkle, Fluttershy, Rarity, and Pinkie Pie came over.

"Aw, she looks so cute," said Fluttershy.

Rainbow blushed. "No I don't!" Then, she farted loudly. FFFFRRRT!

All the girls laughed, even Rarity. Rainbow was unashamed of this, she took pride in her farts being as loud, long, and stinky as possible.

However, after about five minutes of non-stop farting, to which Rainbow was just starting to have fun, her farts became wetter and stinkier, and some of them left her underwear feeling dirty.

"We need to get you to a bathroom fast!" said Pinkie. "Oopsie, I forgot... your potty is all around you!"

"Applejack, you don't seriously expect me to..." BBBRRRRT! "...make a mess, do you?"

"Darn tootin," said Applejack.

Rainbow let out several dirty wet farts, some of which were more than a fart. She tried to hold it in, but once again it was a lost battle. Rainbow soiled herself, feeling it squish in her shorts and underwear under her diaper. It wasn't quite diarrhea but it felt very wet, and usually after something like this she would have to wipe 20 times. It was unpleasant enough when there wasn't any toilet paper, but this was on a whole new level. She blushed at the fact that she pooped her shorts in front of all her friends, but a part of her took a bit of pleasure in being so dirty.

Everyone giggled, then Applejack lay Rainbow on the ground, removed her diaper, and put on a new one over her wet, soiled shorts.

"Hey! What's the point of that? I still have poop in my shorts! That's what needs to be changed!"

"I'll change you however I please," said Applejack. She patted Rainbow's butt.

"Before you put her in her chair, I made the perfect outfit for her," said Rarity. She reached into her bag and brought out a pink onesie with rainbow lightning bolts on it.

"I like the rainbow lightning bolts but a pink onesie?" said Rainbow Dash.

"Oh, you will look absolutely smashing in it," said Rarity.

Rainbow groaned and put the onesie on over top of her diaper, shorts, and T-shirt. As soon as it was zipped up, Rarity removed the zipper from the top. "Detachable zippers! Now you have to stay in this until the seven days are up!"

"R-Rarity! Then Applejack can't change my diapers, and they'll leak and get this outfit all wet!"

"I am sure you will look adorable wetting that onesie."

"Applejack?"

"Fine by me," said Applejack. She picked Rainbow up, patted her rear end, and put her back in her chair.

After Rainbow drank five bottles of cider, Applejack said "How would y'all like to go for a walk in the park?"

The girls all made sounds of agreement.

"I'm not walking in the park like this," said Rainbow.

"Course not," said Applejack, and she put Rainbow into a baby stroller. Rainbow blushed as the girls walked outside, Applejack moving the baby stroller.

They had just reached the park when Rainbow felt an intense urge to pee. "Applejack, I have to go to the bathroom!" She should have known it wouldn't do any good but she could at least make an effort to keep from wetting herself outside.

"Then just go," said Applejack. The girls all giggled.

"I don't wanna wet myself outside!"

"This is your first time wearin' that diaper. It's not gonna leak this time. Remember when you peed the same diaper twice in a row?"

"Let me out of here so I can run back to the house! It's not like I can avoid wetting myself, Rarity removed the zipper from the-"

Applejack put a pacifier in Rainbow's mouth. Rainbow suckled on the pacifier, admitting to herself she was enjoying it. And as for all the extra stuff Applejack was doing to her... well, she probably would have done exactly the same to Applejack if she'd won. She hoped she'd win next time so she could get back at her.

As they walked through the park, anyone who walked by them giggled or chuckled when they saw Rainbow, which made her blush with embarrassment. She still had to go to the bathroom really badly, but due to the pacifier she wasn't feeling like fidgeting. In a matter of minutes, Rainbow peed, feeling the warm wetness spread through her shorts and diaper again. As the diaper contained the wetness, her onesie stayed dry. The girls could hear the hissing sound and giggled.

"Looks like you don't have to go to the bathroom anymore," said Applejack. Rainbow blushed.

...

The following morning, Rainbow woke up. Applejack wasn't tying her up anymore, she wasn't removing this onesie before her week was up. Speaking of, she felt her onesie, which was a bit wet at the crotch and butt. It had been dry when she fell asleep. Not only was her diaper overflowed the point where it would leak now, but she had peed in her sleep. She whimpered. How could this have happened to her? Though, a part of her took a sort of naughty pleasure in it.

Applejack woke up. "Good morning, Rainbow. Did you sleep well?"

"I slept wet."

"Yeah, them shorts gotta be pretty soggy by now."

"No, I mean... I wet the bed."

Applejack chuckled. "I'm not all surprised since you've been peeing yourself several times a day now. I'm sure it'll stop shortly after things get back to normal."

"S-Shortly after?"

"Yup. Don't worry, you're mighty cute when you wet yourself."

Rainbow blushed but smiled.

As the day progressed, Rainbow peed twice more before supper, wetting her onesie further. For supper, Applejack cooked a big plate of chili.

"Not chili!" said Rainbow Dash. "That stuff gives me really bad diarrhea!"

"I know," said Applejack. "Eat up!"

Rainbow ate the chili with her hands as messily as she could, dirtying her onesie, and drank three bottles of cider to wash it down. It wasn't long before she was farting, several dirty wet farts that she couldn't tell whether they were more than a fart because her shorts were already soiled. She didn't bother asking Applejack to let her use the bathroom. Even if Applejack had the zipper, she already knew what the answer would be. She farted for six minutes before noisily filling her shorts with explosive diarrhea.

Applejack chuckled while Rainbow wiggled her messy rear end around. She thought the first time she soiled herself was messy but this was far worse, and smelled even more foul. It felt like she was sitting in a mud puddle, and horse manure smelled better than she did right now. She groaned, and a sloppy wet fart made its way out of her.

...

Rainbow woke up on the morning of the final day. She immediately peed, soaking her onesie more, as her diaper had been peed in so many times it was hardly more absorbent than panties now. Underneath her onesie she was very wet and very soiled, and smelled awful. As she had not washed, she stank of body odor in addition to pee and poop.

The other girls were all sleeping over, and were all awake at this point, as Rainbow discovered when she got out of bed, a visible stench emanating from her.

"Marvelous, you're awake," said Rarity. She reattached the zipper to the onesie, and Rainbow immediately unzipped it, took it off, and removed her soggy diaper, which was dripping.

"I really need a bath," said Rainbow.

"Yes, you do," said Rarity.

Applejack took her to the shower, turned the shower head on, and, climbing into the shower in her jean shorts, rinsed the mess out of Rainbow's shorts. Rainbow sighed of pleasure at this. Once Rainbow was rinsed off, Applejack filled the tub with warm, soapy water, and they both sat down in the tub. Rarity washed Rainbow's hair with shampoo while Applejack washed the rest of her with soap. Rainbow really enjoyed this. Then she got on all fours and Applejack poured a large dollop of soap onto her tush and started rubbing with both hands, coating her stinky shorts in suds. Rainbow sighed again. It felt so good to get clean after how dirty her shorts were.

Applejack washed Rainbow's butt for over 15 minutes before she was able to get the smell out, and then after rinsing off again, Rainbow dried herself enough with the towel so that she was not dripping.

"That was the most embarrassing week of my life, but... I suppose it was kind of fun," said Rainbow. "Once I stop wetting the bed, I'll challenge you to a rematch with the same stakes!"

"You're on!" said Applejack.

Every day Rainbow practiced at the racetrack. She wet the bed the night of her bath, the day after, and two days after that, but afterwards she woke up dry every time. Once she was sure, she and Applejack had their rematch... and Rainbow won!

"This is gonna be so much fun," said Rainbow as she held up a diaper.

"Wait, I gotta pee something fierce," said Applejack. "Can I go to the bathroom first?"

"This is only the beginning," said Rainbow as she put the diaper on over Applejack's sweaty jean shorts and made her put the pink onesie on over top and detached the zipper. It was dry but smelled of pee, as it had not been washed since Rainbow had worn it. "This is gonna be a wet and messy week for you!"