Rainbow Dash was laying on her bed in her pajamas, talking to Rarity on her cell phone.

"So, you doing anything tomorrow?" Rainbow asked Rarity.

"As a matter of fact, tomorrow's my day off," said Rarity.

"You should totally come over. We could hang out and have lots of fun. Maybe stay the night."

"Most definitely," said Rarity.

"Awesome. Well, it's bedtime for me." It was currently midnight.

"Good night, Rainbow Dash."

"Night, Rarity. See you tomorrow."

"See you tomorrow."

Rainbow Dash and Rarity hung up. Rainbow let out a loud fart, then climbed under her covers and fell asleep almost immediately.

...

Rainbow Dash woke up at 8:00 really needing to pee. She considered wetting the bed, but she decided she'd save this for tonight when Rarity was over. It'd be more fun if it was a rarity. So Rainbow climbed out of bed and ran to the bathroom, holding herself with one hand. She had to pee like a race horse. She loved using this expression ever since meeting Princess Twilight.

She entered the bathroom without closing the doors behind her. She was just positioning herself in front of the toilet when a figure with a werewolf mask rose up out of the tub and let out a bloodcurdling howl.

"AAAAAH!" Rainbow Dash was startled. Her heart skipped a beat and she wet her shorts. However, after a few seconds, Rainbow recovered, aside from still peeing uncontrollably. The figure in the werewolf mask had white skin, purple hair was visible, and she was wearing a sexy skintight black unitard. She smiled. "Good one, Rarity!"

Rarity removed her mask. "I hope you enjoyed that as much as I did."

"I did. And I couldn't stop my stream if I wanted to." Rainbow chuckled, still peeing. "How long were you in that tub?"

"The minute you hung up last night I snuck over to your house, quietly entered with the key you gave me, and I was waiting there ever since."

"Not so easy waiting so long, is it? But it sure is worth it. Did you wet yourself?"

"I drank a large amount of coffee to stay awake for the whole night so I wouldn't miss you coming in. So, about an hour in I needed to go pretty badly. I held it until I wet my unitard. You probably would have liked the sight of me fidgeting so hard in the tub trying not to make a sound." She giggled.

"I probably would have," said Rainbow. "I was squirming pretty hard when I was in the tub." She chuckled.

"And about two hours ago by my estimate, I had a really bad case of diarrhea."

Rainbow only just noticed the foul smell in the room that made the pee smell hard to notice. "Nice," she said, with a chuckle.

"It was rather messy, but also kind of fun." Rarity giggled, feeling the filled seat of her unitard.

Rainbow finished peeing, and suddenly felt an urge to poop as well. She grunted and soiled her shorts with hyperscat. "Ahhhhh..."

Rarity giggled. With a PLORP, she released a little more diarrhea into her wet, stinky, heavily soiled unitard.

"We really need to take a bath," said Rainbow Dash.

"Ooh! Bathtime already! I could wet myself with excitement, if I hadn't already emptied my bladder into my outfit."

Rainbow dumped her mess into the toilet while Rarity rinsed the diarrhea out of her outfit in the shower. Then she filled the tub with hot soapy water, and they washed each other the same way as before. They spent extra time scrubbing each other's butts with extra soap, and they both really enjoyed being on each side of it. Rarity farted in the tub again before they were done.

After that, Rainbow put on a skintight pair of black pants and her usual shirt, while Rarity stayed in her wet unitard and blow dried herself. Underneath Rarity wore pink panties, and Rainbow Dash wore gray boyshort panties. So their day of fun began.

First they had a tea party. They drank lots of tea while making fun conversations, and occasionally farting.

Soon, Rainbow Dash said "I have to go to the bathroom!"

"How badly do you need to go?" Rarity asked.

"REAL bad." Rainbow fidgeted in her seat.

"Well, too bad. Girls who fart at tea parties don't get bathroom privileges."

"But I really really really REALLY gotta go!"

"As a matter of fact, girls who fart at tea parties also get a spanking."

Rainbow's heart raced with excitement. "Can I go to the bathroom first? I'm gonna wet my pants!" But of course she wanted Rarity to deny her.

"Over my lap, now."

Without hesitation, Rainbow climbed over Rarity's lap. Rarity giggled quietly at how much Rainbow was into this. She also liked the sight of Rainbow's tushie in those skintight pants. Rarity raised her hand and slapped Rainbow's butt as hard as she could.

Rainbow felt her bladder spasm with the swat, and Rarity continued to spank her. Rainbow kicked her legs as Rarity swatted her rear, and after seven swats, Rainbow was wetting her pants. She peed like a race horse, unable to stop her stream even if she wanted to, and soaking the legs of Rarity's unitard.

Rarity didn't mind of course, she liked the warm, wet feeling of Rainbow Dash peeing on her.

Rainbow Dash also took pleasure in the dirty feeling of wetting herself while being spanked. She loved it all. Each swat on her rear end, the involuntary peeing, her pants getting soaked...

After Rainbow finished peeing, Rarity swatted her three more times. "Did you learn your lesson, Dashie?"

"Yes. I'm such a dirty girl. And I peed my pants." Rainbow chuckled and continued laying on Rarity's lap, her butt sore and her pants sopping wet. A long, wet fart made its way out of her.

Rarity slapped Rainbow's butt one more time. "You are such a farty girl," she said with amusement in her voice.

"Sorry. I couldn't help it." But Rainbow had enjoyed that swat even though it hurt.

Rarity patted Rainbow's butt lightly. "Now that you've learned your lesson, how would you like a butt massage to soothe the pain in your rear?"

"I'd love that." Rainbow got on all fours and Rarity rubbed her butt. Rainbow felt the pain go away and took pleasure in this.

Rarity thought Rainbow's butt looked just as sexy in those pants as in her pajama shorts.

Once Rainbow's butt massage was done, Rarity said "Ooh... I have to use the bathroom."

"We're going straight back to the tea party," said Rainbow.

They sat at the table and each drank another cup of tea. Soon Rarity was really fidgeting. "Dashie, can I PLEASE use the bathroom?"

"You're staying right here."

"But I have to pee really bad!"

"Hey, didn't you also fart at this tea party?"

"Maybe?" Rarity winked, crossing her legs and fidgeting hard even though her pants were already wet with Rainbow's pee.

"You need a spanking, you farty girl."

"Can't I use the bathroom first? I don't think I'm gonna make it."

"Tough. Over my lap."

Rarity climbed over Rainbow's lap. She was so excited to get this spanking she peed a little, but not much.

Rainbow slapped Rarity's butt over and over. Rarity squealed with each swat, taking pleasure in it. It only took four swats before Rarity was peeing full force, her stream almost as strong as Rainbow's. Rarity couldn't stop it, but she didn't try to, she was enjoying the dirty feeling of peeing her unitard while being spanked. Her face had a look of absolute pleasure on it as Rainbow continued to spank her and she continued to pee uncontrollably.

Rainbow stopped spanking three swats after Rarity finished peeing, just as Rarity had done to her. "Have you learned your lesson yet?"

"Yes," said Rarity. "My rear end hurts, and I'm soaking wet."

Rainbow patted Rarity's butt lightly. "Poor girl. You need a butt massage."

So Rarity assumed the position and Rainbow caressed her soft tush. She also enjoyed Rarity's butt in her unitard as much as her shorts. Rarity let out a boisterous wet fart in Rainbow's face. She blushed but giggled, while Rainbow inhaled deeply through her nose.

Once Rarity's butt massage was over, they continued to have fun together. They drank lots of tea, cider, and soda, and the next time they needed to pee, they held it to see each other squirm. They sat in chairs they set across from each other and fidgeted hard with their legs crossed and pained expressions on their face - but they loved every second of it. The desperation, and the imminent wetting, as well as seeing each other in this position.

Rarity having held to bursting point earlier today, her bladder was the first to give out and she peed in her already-wet unitard. Seeing Rarity lose it made Rainbow lose it. She was unable to hold back her stream as it came out full force and soaked her already-wet pants. Both girls giggled at the sight of each other wetting themselves, and took pleasure in the warm, wet feeling, as well as the naughty feeling of it.

They continued to have fun, and for the rest of the day before they changed into their pajamas, if they needed to pee they just went in their pants. Rainbow Dash ate a prune with dinner and pooped her pants with hyperscat. She sat down and wiggled her butt around in her mess, enjoying the senstaion. She had messed herself really bad, and both she and Rarity liked it.

After they changed into their pajamas, they stayed dry until they climbed into bed. As expected, Rarity wet the bed, and when Rainbow woke up really needing to pee, she held it until Rarity woke up, then peed her shorts full force, which both she and Rarity took pleasure in. They laid in bed in their wet state for an hour, farting several times, then they made their way to the bathroom to take their usual bath in their wet pajama shorts. During which both silly girls farted in the tub.