A week later, the girls had a sleepover at Rainbow Dash's house.

When she was sure all the other girls were asleep, Sunset Shimmer quietly tiptoed to Rainbow Dash's room.

She found a white pair of panties in her underwear drawer, took a container of cream cheese frosting out of her backpack, and soaked them in it. Then she dried them with a blow dryer she had brought. Because they were white, no one could tell what she had done, unless they sniffed it. She put these panties at the top of the drawer.

As she was sneaking back to her sleeping bag, she suddenly stopped in her tracks.

Rainbow Dash was awake, with a bowl of water, about to put Pinkie's hand in it. She turned around.

"Sunset? What are you doing up?"

"Hi!" Sunset said nervously. "I had to go to the bathroom really badly. I'm feeling better now, so I'll go to sleep."

Once Sunset was in her sleeping bag, Rainbow put Pinkie's hand in the water bowl.

Nothing happened.

"I'm awake!" said Pinkie. "You didn't think I was gonna forget the last time you did that, did you?"

Rainbow was forced to admit defeat tonight. Maybe she'd try something on Rarity next. But not Fluttershy. Next time they slept over at Applejack's house she'd put Rarity's bed in the mud.

...

The next morning, the girls changed into their outfits. Rainbow wore her usual black compression shorts under a pink skirt, and picked her panties for today from the top of her underwear drawer.

They ate cereal for breakfast today.

Pinkie sniffed. "I smell cream cheese frosting!"

She sniffed Sunset's butt. Sunset giggled.

"Nope, not Sunset this time!"

Pinkie sniffed the other girls' butts, coming to Rainbow Dash last.

"Yup! Dashie's butt smells like cream cheese!" She sniffed deeply.

"Good one Sunset," said Rainbow Dash, finding the whole thing to be funny.

"Now we're even," said Sunset, though she didn't sound annoyed at what Rainbow had done last week, nor was she.

"Frosting is so tasty!" Pinkie lifted Rainbow's skirt and started licking her butt.

"Pinkie what are you doing?" said Rainbow.

"Mmmm! Your tushie tastes like cream cheese too!"

"You do realize I sweat in these shorts too?"

"Adds a bit of a salty taste to it!" And she was careful to only lick her buttocks.

"Pinkie Pie, you are so random." But Rainbow was starting to find it amusing, and chuckled.

Pinkie sniffed, and resumed licking. Until it seemed all the flavor was gone.

"Aw, it lost its taste," said Pinkie. She sniffed Rainbow's butt. "But it still has a bit of the smell!" She slapped Rainbow's butt, which Rainbow liked.

Fluttershy couldn't help but stare.

...

Later that afternoon, Fluttershy soaked her pink panties in vanilla frosting, changed into a short, skintight pair of green shorts, and knocked on the door of Pinkie's house.

She walked home very satisfied, and the back of her shorts sticky with slobber.

She was startled when a rainbow blur zoomed by her.

Rainbow Dash, realizing how much she had enjoyed Pinkie licking her butt, had put some extra cream cheese frosting down her shorts, sat on a cake, and sped over to Pinkie's house.

Author's Notes:

Yeah, I averted Pinkie wetting herself because that is not the fetish I was going for in this story, and I've written way too many stories about that already.

Also, I'll say Pinkie is wearing her usual pink dress for both chapters.