On the night of July 22nd, Rainbow Dash, Rarity, Pinkie Pie, Fluttershy, Applejack, and Sunset Shimmer were having a sleepover with their new friend, Twilight Sparkle, at Rarity's house. They were all wearing their pajamas except Rainbow Dash, who didn't have any. She had wiped her shorts of the drool with lots of tissues and let them dry in the summer heat.

Rarity sprayed air freshener in the room, so the room smelled nice in spite of Rainbow's odor and Sunset's farts. Sunset was very gassy tonight, but she kept her farts silent so as to not offend Rarity.

They chatted, telling Twilight many of their stories. In the middle of one of Applejack's stories, Fluttershy quietly left to go to the bathroom, and returned with her pajama pants dry.

"And, I really like this guy, Flash Sentry," said Sunset. "I'm afraid he won't want to go near me because of my farts."

"Darling, you can always suggest that he carry a can of air freshener with him," said Rarity. "Maybe... tell him, and if it disgusts him too much, he isn't the one for you. Besides, he might even be into it, like Rainbow's boyfriend likes everything... how to put it delicately... unladylike... about her."

"Really?" said Twilight.

"Yeah," said Rainbow. "It's funny cause I thought I didn't have a chance with him so Rarity gave me a b... a makeover and had me take a long shower."

"No, I gave her a bath," said Rarity. "Then a makeover. Oh, she looked simply gorgeous, and she smelled very nice." She chuckled a bit. "I wonder how long you'd have been able to stay like that, even for him?"

"I did kinda like it a bit. I could've stayed that way forever. I only went back to being grungy because Cherry liked it."

"You seemed very overjoyed and relieved about it. Face it, Rainbow Dash. You're a great friend, but you're dirty and smelly by nature. I don't think you'd have been able to keep that girly girl thing up for long."

"Probably longer than you'd be able to go without washing!"

"I very much doubt that. You like being dirty way too much. No offense," she added delicately.

"Is that a challenge?"

"What?"

"How about we switch places, so you stop washing and I start washing like you? I bet I could outlast you!"

"I can't believe I'm about to say this, but... you're on! Starting tomorrow!"

Rainbow spit on her hand and held it up for a high five.

"Ew, Rainbow, no! Remember everything I taught you about being a girly girl. If you can't, I'll win the bet easily. What are we betting, exactly?"

"If you wash any part of yourself other than your hands or hair, even once before I've done anything too 'dirty', you have to pee in one of your best dresses and wear it for the rest of the day."

Rarity shuddered. "And if you do anything against my rules of being clean before I wash, you have to let me wash your rear end in front of all our friends, and THEN wear a frou frou dress for the rest of the day."

It was Rainbow's turn to shudder. But, she was confident that Rarity wouldn't be able to stand her own smell after not washing for even two days. "All right, you're on!" Using her clean hand, she shook Rarity's hand.

"Well, here are the rules," said Rarity. "You have to shower every morning. With soap."

"EVERY morning?"

"That's right. And after every one of your races, soccer games, or any other athletic activities that make you sweat. You will change into my gym attire for those."

"So... I'll be wearing your gym clothes?"

"That's right. And my pajamas when you go to bed, and my dress when you're not doing either. Because you simply can't smell clean in that foul outfit. And, every three days, wash the dress and the gym shorts in the washing machine. You... do have a washing machine, right?"

"Yeah, but I never use it."

"I'll show you how!" Rarity said excitedly. "I'll also give you a set of underwear. Change it every day. I imagine your only pair of underwear is the one you're wearing now."

"How did you guess?"

"I can help make sure she doesn't cheat," said Twilight. "I'll set up a waterproof camera in her shower. To record only when the shower water is on."

"No way! I don't want you to see my naked rear end!"

"Then wear your underwear in the shower," said Rarity. "That will also ensure that they are washed."

"Oh. That's a little better."

"And also wash my pajamas every Sunday. And apply deodorant after every shower."

"You got it! Now, for your rules! You can't shower or take a bath... at all. Not even a dip in a pool, fountain, or lake. The only parts of you you're allowed to wash are your hands and your hair, with dry shampoo. And brush your teeth, of course."

"What if I get... really dirty?"

"I'll let you know if it's something I'd usually wash for, and stand in the bathroom as you shower. WITHOUT soap. On that note, you'll be wearing my outfit."

"What? Your outfit is filthy! And you just had a pig drool on your... I mean... I can handle it."

"And don't change out of it for ANY reason. Only pull my shorts down to go to the bathroom."

"Tell me I can at least use toilet paper."

"Of course. You don't have to do anything I wouldn't do."

"Can you maybe keep your skirt at home so you can smell it every day and remind yourself what you used to smell like?"

"Sure. But you're wearing this shirt, jacket, and shorts as they are. And no deodorant or perfume either."

"I can set up an alarm in her shower that will alert me if it's turned on," said Twilight.

"And," said Rainbow, "unless you have plans to hang out with one of our friends, or are busy making dresses or selling them at the time, whenever I run a race, you will enter it with me and run as fast as you can. Just to make you sweat. And sit outside during the football games. I'll give you enough water bottles for it."

"Very well," said Rarity.

Then, Rainbow farted loudly. Pinkie burst out laughing.

"Um... be careful, Pinkie Pie," said Fluttershy timidly.

"One more thing," said Rarity. "You are absolutely not allowed to break wind out loud in our presence. You are to hold it in around others, and do it silently if you can't. To make it easier, I will make a list of foods that you should avoid to reduce your... gassiness."

"In that case," said Rainbow, pausing to let out a slightly shorter and quieter fart, "you have to fart loud every time. Well, almost every time, I don't expect you to be perfect. If you go a day without farting in front of one of us, you lose."

"What?"

"And, for every lunch and dinner, either eat what's on the list of stuff I'll avoid, like beans, or else something with a bit of fart powder sprinkled on it."

"I'll provide the fart powder!" said Pinkie.

"Fine," said Rarity. "But you lose if you have an accident in my dress from laughing at it."

"Who do you think I am, Pinkie Pie?" said Rainbow Dash.

"If you recall the day that you met her..."

"It was ONE TIME! I had a lot to drink that morning and I was gonna go to the bathroom as soon as I was friends with her. Plus I wasn't expecting her to fart. I've laughed a hundred times at Pinkie and Sunset farting after that and kept dry."

"If you say so. Are there any more terms to our dare?"

"No, that's it. Do we have a deal?"

Rarity shook her hand again. "Deal!"

"Now that that's done," said Pinkie, "you got a spare set of pajama pants, Rarity?"

"Of course, darling."