Author's Notes:

I think this is a fetishy branch of the "messy" side of my wam interest, like the soap/washing for the "wet" side.

It was the summer following the Equestria Girls' graduation from Canterlot High. Sunset Shimmer had seemed like she'd fallen in love with Flash Sentry, but realized she really liked Pinkie Pie. When Sunset plucked up the courage to confess her feelings for Pinkie, Pinkie kissed her on the cheek.

They had been going out for quite some time, and soon they were feeling sexual attraction to each other. But Pinkie's idea of a fun time in this way, Sunset would find to be more interesting than vanilla sex.

Sunset arrived at Pinkie's house one evening. Streamers went off and balloons were in the air as though it was a big party, although the only other person in the house was Pinkie Pie, wearing a white and pink T-shirt and a short, tight pair of jean shorts. Whenever she wore these Sunset couldn't stop staring at her butt.

"Hi, Sunny!" said Pinkie excitedly. "Are you ready to see what I have in store? Are you? Are you?"

"I'm sure it will be interesting," said Sunset. "Just let me change into my pajamas first." Sunset knew Pinkie liked the way her butt looked in her pajamas even more than the jeans she was wearing now.

They were at the point that they could undress in front of each other without shame. Sunset seemed to enjoy stripping down in front of Pinkie. She did not remove her black bra and panties before putting her pajamas on.

"How do I look?" said Sunset.

"Ready to have fun!" said Pinkie.

"So, which fetish will we play out?" said Sunset, wondering whether she'd enjoy it as much as Pinkie. She hoped she would.

"First things first," said Pinkie. She pointed at the table where a small cake sat, with chocolate frosting on it. She cut the cake in two and put one half each on a different plate on two chairs close to each other. "Snack time! And don't worry about eating neatly. I'm the only other one here. Eat as messy as you want!"

Pinkie and Sunset sat down at the table. Sunset looked at the cake. It had a lot of frosting on it and a strawberry filling inside.

"Dig in, Sunny!" Pinkie started devouring the cake very messily with her hands, not caring how much frosting she got on herself.

Sunset chuckled a bit, and picked up a piece of cake with both hands and stuffed it into her mouth. A bit of the filling and frosting dripped onto her shirt, but she didn't mind. She began to eat faster and messier, finishing about a minute after Pinkie did.

"Was that delicious or what?" said Pinkie. Her arms, legs, shirt, and shorts had bits of chocolate frosting and strawberry filling on them, as did Sunset's pajamas.

"It sure was," said Sunset. "What now?"

"I baked a few more cakes, but not for eating. Well, not yet anyway!" Pinkie took two similar chocolate cakes off the table and set them down on the floor.

"What are we going to do with them?" said Sunset, with a feeling of excitement because she knew this would be interesting.

"We're gonna sit on them!"

Sunset had never sat on a cake before. The thought of it intrigued her. It would be pretty messy, but Pinkie seemed to like it, and she hadn't exactly disliked eating the cake in a messy way. Pinkie hadn't even forced her to, she did it on her own.

Pinkie sat on one of the cakes, which squished under her butt. Sunset could feel herself getting aroused. Pinkie wiggled her butt against the cake for a few seconds, before she stood up. She turned around so that Sunset could see the brown spot on her rear.

"Wanna try it?" said Pinkie, slapping her frosting-covered butt.

Sunset turned around, her heart beating rapidly, and sat on the other cake. She could feel the wet, squishy feeling under her butt, which felt weird, but she liked it. After a few seconds, she remembered what Pinkie had done, and wiggled her butt against the squished cake under her. She liked this feeling too.

She remained in a sitting position for longer than Pinkie Pie had, and then she stood up. She turned around so Pinkie could see the state of her behind.

Pinkie giggled. "You look like you soiled yourself!"

Sunset chuckled. "So do you. That was pretty fun."

"In that case, I can't wait to do the next part! It's not as fun if I'm the only one there."

"Ooh, what is it?"

"Get down on your knees and face away from me."

Sunset did so, her heart pounding with anticipation and curiosity as to what would come next.

Pinkie took one of two blueberry pies with whip cream on top, quietly tiptoed behind Sunset, and smashed the pie in her butt.

Sunset squealed in surprise. Then she laughed. "I should have seen that coming."

Pinkie rubbed the pie in Sunset's tush for a while, and Sunset moaned with pleasure. Then Pinkie stopped. "Now do it to me!"

Sunset stood up and found the other pie on the counter while Pinkie got on all fours. Sunset smashed the pie in Pinkie's rear end, and Pinkie let out a squeal that could have either been the sudden wet impact, or out of pleasure.

"You really like this, don't you?" said Sunset, rubbing the pie against Pinkie's butt until the back of her shorts was saturated.

"Yep! Sploshing's really fun!"

"Sploshing?"

"That's what rubbing food on your body is called."

"I think it's really fun, too."

"Ooh! I just thought of something else that I couldn't exactly do on my own."

"What?"

"Let's lick all the frosting and whip cream off each other!"

"Good idea! Can I go first?"

"Sure!"

Pinkie stayed in her current position as Sunset licked Pinkie's butt. The fabric of her jean shorts would have felt harder when dry, but being covered in frosting and whip cream it was very soft. Sunset enjoyed the taste, and also felt aroused by the fact that she was licking Pinkie's butt.

Pinkie was really enjoying this, too.

Sunset wasn't one for licking the anus, but Pinkie's shorts acted as a shield from it.

When Sunset was done, the back of Pinkie's shorts was wet and sticky but most of the frosting and whip cream was gone.

"My turn!" said Pinkie. "Wait, hold on a second." Pinkie grabbed a can of whip cream and sprayed it down her shorts. She sat down, feeling it squish under her with a squelching noise. Pinkie giggled, then put some pieces of the cakes and pies down her shorts as well. "Now I'm ready!"

Sunset got down on all fours, and Pinkie licked Sunset's butt furiously.

"Ooh," said Sunset, who wasn't expecting Pinkie to lick faster than her. But, she should have expected it. She was Pinkie Pie.

The fabric of Sunset's pajamas was smooth even if it wasn't covered in frosting and whip cream.

In about half the time it took Sunset, Pinkie finished licking Sunset's rear mostly clean. Once she was done, Sunset took the whip cream and sprayed it down her pants, and she and Pinkie sat down, enjoying the squishing feeling under them.

"That was..." said Sunset. "I never knew it could be so much fun."

"I don't do it a whole lot," said Pinkie. "But every once and a while is fun!"

"I can really see why you're into this."

They stood up and rubbed their butts against each other. Then they walked into the shower, not bothering to undress. They scrubbed each other clean with soap, taking extra time on each other's butts. Then they stepped out of the shower and took turns blow drying each other. Once they were mostly dry, they watched a movie, and then climbed into bed and fell asleep.