Rarity was wearing a sports outfit consisting of a blue tank top and skintight pink shorts. Today she was running a race with Applejack. Applejack wasn't wearing a sports outfit, but Rarity wanted to. A small part of the race was to test her sports outfits out, but mostly it was having fun with Applejack.
They ran five laps around a long racetrack. When Rarity crossed the finish line after Applejack, they were panting, dripping with sweat. Rarity more so than Applejack as she was less athletic.
"Good game, Rarity," said Applejack.
"That was rather fun," said Rarity, giving Applejack a hoof bump. She sniffed her armpit. "I need a bath. I smell awful."
Applejack sniffed her and blushed lightly. "Y'all smell just fine." She winked.
For a while, Rarity was sure she had a crush on Applejack. And it seemed that Applejack liked her smelling bad? Well, this was only a mild sweaty smell right now, but if she was right... if she smelled really bad...
"And I must say, you look darn fine in that outfit." Applejack slapped Rarity's butt with her hoof.
Rarity's heart started beating even faster. Applejack had never slapped her butt like this before. Was she starting to become attracted to her too? There was only one way to find out.
After they finished hanging out, Rarity went to her home. She decided she'd stop washing for a while and see if Applejack started sniffing her or swatting her rear more. And, she decided to leave this outfit on for it all, since Applejack liked it so much.
...
Days went by. Rarity didn't wash, or remove her outfit, except to go to the bathroom. When she wasn't making outfits or hanging out with her friends, she was running more laps, both to train for future races with Applejack, and to sweat more.
She raced Applejack again two days after their first race. This time Rarity was closer behind Applejack as they crossed the finish line.
As they did a hoof bump, Applejack sniffed Rarity. Rarity smelled worse than a pony who had just sweated running a race. She smelled like she hadn't washed for a couple days. Applejack blushed, and her heart was beating faster.
"Wanna do rump bumps after a race instead of hoof bumps?" Applejack asked.
"I don't see why not." This was a good sign.
Rarity and Applejack did a rump bump, which Rarity enjoyed a lot.
...
It was now a week after Rarity stopped washing. Her mane and tail were quite messy, her outfit was pretty dirty, and she smelled really bad. Applejack had sniffed her a little more and slapped her rear end a few more times, but she hadn't said anything yet.
The Main 6 were sitting around the table in Twilight's castle.
"What's that smell?" said Pinkie. "Did you fart, Rarity?"
"Goodness, no," said Rarity, who couldn't help but notice Applejack blush. Was it because Pinkie was commenting on Rarity's smell, or did Applejack think Rarity farted?
Pinkie sniffed Rarity. "Yep, the smell is coming from you!"
Rarity blushed a little. "Well, I... I'm doing a little experiment where I stop bathing, to see whether the smell of body odor can wash out of my new sports outfits easily. At most I'll do it for one more week and then wash them, so I hope you can put up with the smell until then."
"Of course we can," said Twilight.
"I'd hug you if I didn't smell so foul..."
All the other ponies and Spike gave Rarity a hug. They took one whiff of her and winced slightly, breathing through their mouths. Except Spike and Applejack, who inhaled deeply with their noses.
After they finished their discussion, Rarity and Applejack walked outside together.
"What do you say we race again?" said Rarity.
"I'd love to, but I got lots of work to do around the farm. But we can do it tomorrow morning if you feel like it."
Rarity suddenly farted loudly. FFFFFFRRRRRRRT!
Applejack blushed and looked in Rarity's direction. "Rarity, did you just..."
Rarity also blushed and giggled nervously. "Excuse me. I held that in for the entire meeting."
"Don't worry your pretty li'l head about it, Rares. We all fart sometimes." Applejack slapped Rarity's butt again with her hoof. "See ya tomorrow!" She walked away.
Rarity felt so dirty, but she was sure Applejack was loving this. Maybe there was another reason Applejack was sniffing her, and maybe she just casually slapped ponies' butts. But, it didn't seem that way.
...
The next morning, Rarity woke up. Her bedroom was full of her smell. She considered what to have for breakfast, and then noticed the can of beans she had bought last night. Applejack had blushed and slapped her butt when she farted in front of her. Did she like to see her fart? There was only one way to find out.
...
Rarity met Applejack at the racetrack.
"Phew, Rarity, you smell real bad," said Applejack.
"I hope you don't mind."
"Not at all. You stay like that for as long as you want." Applejack blushed a little.
Then, Rarity let out a loud, wet fart.
PPPPPPPFFFFFFFFFFT!
"That don't smell much worse than you," said Applejack, but her face was turning a little redder.
Rarity farted again, and Applejack slapped her butt with her hoof. Her shorts felt dirty and a little damp, and she loved it.
As if the butt slap was a signal, Rarity let loose with a flurry of explosive wet farts. She blushed lightly; she had never farted this often in front of another pony, but she was sure Applejack liked it, as she remained standing behind her. She was sure none of the other ponies would want to go anywhere near her rear end right now.
"What did you eat, girl?" said Applejack, slapping Rarity's tush again.
"I had some beans for breakfast," Rarity said bashfully.
"Yeah, those will have that effect on you."
"I don't mind if it's just you here."
"Well, in that case, I..."
"Yes?"
"Uh... I'm ready to race."
"Oh. Me too."
They stood at the start line.
"Ready..." said Rarity. "Set..." PPPPFFFFFFFFT!
At the sound of Rarity's fart, they began running. This time Rarity ran ahead of Applejack, who stayed directly behind Rarity. Rarity let out some more farts during the race, and she suspected Applejack was deliberately staying downwind of her.
Applejack could catch a whiff of both Rarity's smell and her farts, and loved every second of it.
As Rarity crossed the finish line for the fifth lap, Applejack, forgetting that that they were on their final lap, slammed right into Rarity's butt. Rarity yelped in surprise, but didn't exactly dislike this. Applejack took one sniff. Rarity's shorts smelled like sweat, body odor, and farts. She let out a sigh of satisfaction as she slid to the ground.
"Are you all right, Applejack?" said Rarity.
"Never been better."
Before she knew what she was doing, Rarity sat on Applejack's head. Applejack didn't resist. She loved the feeling of Rarity's butt against her face. It was so soft. And once again, she got to smell it up close.
Then Rarity let out a short but loud fart, and stood up. "My apologies, Applejack. I don't know what came over me."
"It's all right. I don't mind."
"Applejack."
"Yes, Rarity?"
"Do you-"
BBBBBBBBRRRRRRRRRRRT!
Rarity paused to giggle nervously at this long, loud, deep-pitched fart that had come out of her, and Applejack blushing with a smile on her face encouraged her to continue.
"Do you... like it when I... Oh no."
"What's wrong, Rarity?"
"I need to use the bathroom." She hadn't taken her morning pee today, and had drank a lot of water before the race.
"Let's get you to a bathroom right away!"
Applejack and Rarity ran towards Applejack's house, which was closer. They ran side by side, and Applejack occasionally turned her head to sniff Rarity.
They entered Applejack's house. Apple Bloom was hanging out with the Crusaders, Big Mac was with Sugar Belle, and Granny Smith was announcing some event. So it was just Applejack and Rarity here today.
As soon as they were inside, Rarity started to run for the bathroom.
"Rarity, wait," said Applejack.
Rarity stopped, turning around and pee dancing. "Can you make this fast? I really have to go!"
"What were you gonna ask back there?"
"Can it wait? I don't think I can."
"I'd kinda like to know now."
The smelly unicorn stood a little more still, crossing her back legs. "Do you... like it when I smell like this?"
"Uh... yeah. I kinda have a thing for smelly ponies."
"And what about when I fart?"
"Ah love that too."
"And if it was Rainbow Dash?"
"I'd probably like it a bit, but you, Rarity, you're... I... uh..."
Rarity leaned in and kissed Applejack on the mouth. Applejack kissed her back, getting a nice whiff of Rarity in the process.
A soft hissing sound was heard, and Rarity felt the crotch of her shorts grow warm and wet. She paused, and looked down. A puddle was growing rapidly under her. Rarity was peeing her stinky shorts. She blushed beet red. "I told you I couldn't wait..."
"It's all right, Rares. If anythin'... that kinda makes me like you more."
"Really?"
"Darn tootin'."
"You were trying to make this happen, weren't you?"
"Well, uh..."
Rarity kissed Applejack again. She let out a short fart before she finished peeing. "I don't mind. It actually feels rather nice, and I'll stay like this for another week."
"Rarity, you don't have to do that. I liked you before you started to smell. It just made it harder to resist swattin' your rear."
"Well, I want to. One more week, then you can give me a bath."
"Deal."
...
Later that afternoon, Rarity met with the rest of her friends.
"Did you... wet yourself?" said Twilight, noticing the state of Rarity's shorts.
Rarity blushed lightly. "Well... you see... I thought I should test to see if my outfits can be washed from that as well. Since I've heard stories of some athletes letting it flow while running. And I'll stay like this for another week to make sure it can be cleaned completely."
Rainbow Dash and Pinkie Pie chuckled a bit.
"That sounds like a good plan," said Twilight.
"Yeah, I may have done that in that black pair of shorts once," said Rainbow Dash. "Or twice."
"I hope it wasn't too unpleasant for you, Rarity," Twilight continued.
"Me too," said Fluttershy.
"It wasn't so bad, though it's not something I'll repeat often." Rarity was glad none of her friends were disgusted, nor making fun of her.
...
Another week went by, during which Rarity continued to make herself gassy, and whenever she needed to pee, she just went in her shorts, either where she was if outside, or sitting on the toilet if inside.
By the end of this week, Rarity was twice as stinky as before, and then there was the added smell of urine, which her dirty shorts were supersaturated with.
Rarity and Applejack met up in Applejack's backyard. Applejack had a wooden tub full of warm soapy water. "Ready for your bath, Rares?"
"Am I ever," said Rarity. "I'm a filthy, foul-smelling mess!" She let out a dirty wet fart, and chuckled. "But I do kind of find it fun."
"I am gonna miss you smellin' like this, but you don't have to do it again."
"Oh, I might return to it once and a while." She winked.
Applejack sniffed Rarity one last time, savoring the foul smell emanating from her. "Now, climb into the tub."
"Hold on, I have to go to the bathroom." Rarity closed her eyes and peed, sighing of relief. "Okay, now I'm ready."
Rarity climbed into the tub, still in her smelly outfit, and Applejack poured some water over her head and lathered her mane with shampoo. Then she took a scrubber and scrubbed her back with soap, creating suds. Rarity farted in the tub, and she and Applejack chuckled at the sight of the bubbles around her. Once Rarity's top half was clean, Applejack had her raise her behind in the air, and scrubbed it extra hard. Rarity really enjoyed this. She accidentally farted in Applejack's face, but she knew Applejack liked it.
Finally, after much scrubbing and rinsing, Rarity was sparkly clean and soaking wet.
"Oh, it has been so dreadfully long," said Rarity. "It's nice to be clean again. Can you sniff my rear end for me? I need to be able to tell Twilight if my test was successful."
Applejack sniffed Rarity's tushie. She could smell nothing but a hint of soap, and she couldn't see any stains either. "Yep, all clean." She patted Rarity's butt lightly.
"Splendid."
"Still up for another race?" said Applejack.
"I wouldn't miss it," said Rarity. She farted loudly, and Applejack slapped her behind again.