Author's Notes:

Unlike other chapters, this one has less story to it and more fetish fuel. This chapter was requested by someone who shares three of my fetishes.

Rainbow Dash was having dinner at Cherry's house. Cherry put together a salad for both of them, with steak for himself and beans for Rainbow Dash. He knew how much she loved them, and not just for the taste.

Once they had finished eating, Rainbow having eaten messily as usual, they started to talk.

"And yesterday I made a new friend. Her name is Wallflower Blush. She was actually there when I met all the other girls, except Rarity. And, she loves to pee her pants. But, that didn't stop her from becoming one of us!"

"That sounds great," said Cherry. "Reminds me of that time I tickled you on our first date."

Rainbow blushed lightly and chuckled. "How would you like to sniff my butt?"

Cherry knew this was a signal for a session of buttplay. Much like Sunset Shimmer and Flash Sentry, they hadn't really had sex yet, but they had a lot of fun with this, finding it good enough for now. Rainbow Dash usually didn't like anyone else going near her rear end unless she was farting on them, but her boyfriend was the exception.

Also, not a lot of people wanted to go anywhere near her rear end for any reason other than to wash it. Cherry was the exception to this, too.

Rainbow Dash got down on all fours. Cherry did the same and sniffed Rainbow's butt. It smelled worse than any part of her except her armpits and feet. It smelled like a combination of sweat and farts.

"Your butt sure smells awful," Cherry giggled, slapping Rainbow Dash's butt. This always surprised Rainbow a little, but she liked it.

"Just wait until the beans kick in," chuckled Rainbow.

"Do you want a butt massage while you're waiting?"

"I'd love one!"

Cherry started to rub Rainbow's butt with both hands. Her shorts were dirty and grimy, and he could feel it against his hands. But, he could also feel how firm Rainbow's butt was. And it looked very cute in those skintight shorts, however dirty they were. To him, her grunginess made her more attractive.

Rainbow closed her eyes and sighed, taking great pleasure in her boyfriend rubbing her tush.

And then...

PPPPPPRRRRRRRRT! PPPLLLRRRRRT! BBBRRRRRRT!

Several loud, wet farts erupted out of her. She sighed in relief.

Cherry sniffed. He stopped rubbing and patted Rainbow's behind lightly. "That was a good start. Do it again!"

"You got it!"

PPPPPPPPPPPPFFFFFFFFFFFFFRRRRRRRRRRRRRRRT!

Rainbow chuckled at the sound of her longer, explosive fart.

"That's more like it!" Cherry slapped Rainbow's butt playfully.

He went back to rubbing Rainbow's dirty rump as she continued to let loose with loud farts, some of which were wet and some of which were deeper-pitched.

"Hold on..." Rainbow let out another long fart, which was the loudest and wettest fart yet.

"Whoa, are you all right, Rainbow?" Cherry chuckled.

Rainbow Dash felt her butt. "Yeah, I'm fine."

"When's the next time you're going to rinse in the shower?"

"Tomorrow morning." BRRAAAAPPPFFFRRRPP!

Cherry slapped Rainbow's butt again. "Looks like we picked the right night."

"Actually, I usually would have rinsed off today. But I wanted to smell my worst for you."

"Awww..." He patted her butt lightly, and she farted in his face again. "You didn't have to do that. You still smell really bad after rinsing off. Even without the farting."

"Thanks." She shook her butt a little, causing him to slap it lightly again. "Of course, I don't want to smell as bad as Indigo Zap. I just competed with her in another game a few days ago and she smells almost as bad as she did before I gave her a bath."

"Is she still peeing herself?"

"Of course." FFFFFRRRRRRT!

"Have you done that recently?"

"Not since Applejack and Pinkie Pie threw me into the mud while I was wearing Rarity's dress. But now that you mention it, I really gotta go!"

"Just hold it. The butt massage isn't over yet." He patted her butt again and resumed rubbing it.

Rainbow relaxed, enjoying the butt massage. She farted again and peed a little. She let out a whimper, more of surprise than anything.

"Is there a problem, Dashie?" Cherry asked playfully.

"Not at all!" Rainbow Dash turned her head and winked so he could see it. Here she didn't really care, just like when she had gone to the park with him for the first time. And if he liked it, she definitely didn't mind.

Cherry continued caressing the smelly girl's dirty rump. Rainbow's desperation increased with each minute, but she made no attempt to resist or run to the bathroom.

She'd usually be able to hold it for longer, but between her farts and how relaxing it was to have her butt rubbed, she started to pee uncontrollably. She sighed in immense relief as her stream passed through her shorts and formed a puddle under her.

"Did someone have an accident?" Cherry teased.

"I just couldn't hold it." Rainbow laughed and started to pee harder, enjoying the warm release. For the first time she understood how Wallflower felt. Even though she still wouldn't usually do this. She'd reserve it for every once and a while with Cherry, and unlike Indigo, she'd shower after each time to rinse her shorts of the pee.

Cherry slapped her butt playfully, and went back to rubbing.

...

That night, they slept next to each other, Rainbow not having washed or changed since fifteen days ago.

The next morning, as soon as she was back home, Rainbow turned on the shower, and stepped into it, without undressing or using soap. As she rinsed herself off, she started lathering her hair with shampoo, thinking about how wonderful last night had been.