It was the day after Rainbow Dash and Rarity's hypnosis session with the other ponies, and Rainbow Dash and Rarity stood before each other at Carousel Boutique, having gotten everything set up. Rainbow didn't want to know too much ahead of time though - she wanted it to be a surprise what Rarity did to her.

First Rainbow Dash drank five mugs of cider spiked with fart powder. She would do this part on her own so she would remember the taste of the cider. Rarity's fantasies had never involved Rainbow Dash farting, yesterday she had discovered a new fetish for other mares farting, though she'd still never fart in any way other than silently, away from other ponies, and not under the water (unless she was hypnotized, of course!). She hadn't discovered it earlier because the ponies knew how ladylike she was and never farted in front of her. Well, Fluttershy had accidentally done so once, but her embarrassment overrode anything else Rarity might have felt and all she could think about was making her feel better about it.

Rarity wore the hypnosis bracelet, and, remembering what Rainbow Dash had done to Twilight, Pinkie, and Applejack perfectly well, hypnotized Rainbow Dash the same way.

As soon as Rainbow Dash was in her trance, Rarity had her wear a dress resembling a red tank top and a rainbow striped miniskirt, with pink panties underneath.

"Now, tie that rope around your back hooves," said Rarity. And once Rainbow Dash had done so, she added "Now tie the other end around that ring hanging from the ceiling."

Rainbow flew up and did what Rarity had said.

"Now, stop flying!"

Rainbow stopped moving her wings and fell, so that she was hanging upside-down from the ceiling just above the ground, for Rarity had measured the rope carefully. In her position her panties were clearly visible. Rarity walked over to Rainbow Dash's butt and started caressing it. Rainbow's butt was firm, in contrast to her, but she liked the feel of it a lot.

Then Rainbow Dash farted in Rarity's face. Rarity giggled at this. Her original fantasies had not involved farting, but now that she had the fetish it would always be part of them!

"Do that whenever you get the urge," said Rarity, and she slapped Rainbow's rear end. "And squeal like I would whenever I do that."

Rainbow continued to fart while Rarity continued to rub, slap, or sniff her butt. Eventually, Rarity pressed her head against Rainbow's tush for two minutes. Rainbow farted in her face several times.

Then, Rarity levitated a big flyswatter, and smacked Rainbow's butt with it as hard as she could. Rainbow squealed just as Rarity had said. Rainbow had said Rarity had already made her do this to her, so she knew she wouldn't mind how sore her butt would be when she woke up.

After about thirty swats - Rainbow peed a little on the 26th - Rarity stopped, and planted a sloppy, wet kiss on Rainbow's butt. As Rarity kissed the other side of her butt, Rainbow Dash let out a loud, wet fart.

Rarity giggled. "I never thought I'd say this, but you are SO much cuter when you fart!"

She magically untied the rope around Rainbow's hooves, and she fell on her back.

"Now, sit on that cake," said Rarity, pointing toward a cake she had gotten from Sugarcube Corner which had lots of frosting on it.

Rainbow Dash sat on the cake for about a minute, before Rarity had her stand up. The back of her dress had frosting all over it. Rarity told Rainbow to remove her dress but not her panties. Rarity stretched Rainbow's panties, wedgie style, and then snapped it against her rear. Rainbow let out a high-pitched squeal, and Rarity scooped up as much frosting as she could and put it down Rainbow's underwear.

Then, Rarity put on a similar dress, but pink. "Now, see those ropes on the ground? Tie me facedown using all the ropes. And put a ring on my horn to block my magic. Gag me with the dress you were wearing. Then sit on my head for five seconds, if you can. Then, sit down in front of me until I either rest my head sideways, or you have to pee really badly. If I turn my head, sit on my head for about two minutes. Fart whenever you feel like it. If you have to pee, once you're really desperate, give me a golden shower. Once that's done, un-gag me and I'll give you your next instructions."

Rarity laid facedown next to the ropes. There were five ropes, one each for Rarity's hooves, and her waist. Rainbow tied Rarity down so she was completely immobile, except for her head. Rainbow put a magic-blocking ring on Rarity's horn, and then gagged her with the rainbow dress.

Rainbow walked over to Rarity and started to sit on her head, until Rarity's horn poked her in the butt, and she jumped off her. Rarity was so excited by this that she peed a little.

Then Rainbow sat in front of Rarity, the frosting in her underwear squishing under her butt. Rarity struggled against her bonds, but it was no use. Rainbow had tied her completely immobile, and she loved it.

After a particularly loud and wet fart, Rarity began to worry that Rainbow was running out of gas.

"Mmmmhhhh!" She couldn't speak through her gag. She should have known this, perhaps she just wanted to try it out as part of her bondage fetish. She turned her head so it was on its side. Rainbow stood up, walked over to Rarity, and sat on her head. She liked the feeling of Rainbow's butt against the side of her face, as usual. She could also feel the frosting on her panties.

Rainbow Dash farted loud and wet several times, and once two minutes were up, she stood up.

Rarity had Rainbow sit on her head a few more times, before she started fidgeting. Rainbow Dash needed to pee, but not badly enough yet.

Finally, Rainbow walked over to Rarity, stood above her, and began peeing through her panties all over Rarity, soaking her pink dress, and her mane. Rarity loved the feeling of it. It had been quite a pleasant surprise, though a little embarrassing, when Rainbow Dash told Rarity that she had made her do the same thing to her.

Rarity was feeling a bit of an urge to pee as well, but she decided to hold it for now.

Rainbow Dash removed Rarity's soaking wet gag.

"That was amazing, Dashie!" said Rarity. "Now, here's what I want you to do. As soon as I'm finished giving you your instructions, gag me again. Then, pull down my panties and lick my rear as hard and vigorous as you can for five minutes. But NOT the... asshole. Then..."

Rarity gave Rainbow Dash the rest of her instructions.

Once Rarity was done speaking, Rainbow Dash gagged Rarity again. The gag was wet and tasted of pee, but Rarity didn't mind.

Rainbow Dash pulled down Rarity's underwear, which were soaked with Rainbow's pee, and began to lick Rarity's butt.

"Mmmmmm!" said Rarity through her gag, unable to properly express how much she was enjoying this.

After five minutes, Rainbow stopped licking and pulled Rarity's panties back up, and then walked over to her back left hoof and started licking it.

"MMMMMMMMMHHHHHHHH!" said Rarity, for this tickled a lot, and in her position she couldn't even move.

After two minutes, Rainbow licked Rarity's right back hoof, then each of her front hooves, for two minutes each. The entire time Rarity was yelling muffled screams through her gag, and peed herself a little on the third hoof, but held the rest of it in, as she didn't have to go that badly yet.

Once Rainbow was done licking Rarity's hooves, she lifted Rarity's skirt so her panties were visible, and slapped her butt. After twenty swats, Rarity's butt was a little sore, but Rainbow Dash wasn't done yet! She grabbed the flyswatter in her mouth and swatted Rarity's tush with it as well. With each swat Rarity let out a muffled shriek. It hurt, but she was enjoying it.

Twenty swats layer, Rainbow Dash picked up a whip from the wall, and whipped Rarity's rear end with it. Pain shot through it and Rarity let out muffled screams of pain and pleasure.

But, Rainbow only whipped her ten times. Then she put the whip away, put both her hooves on Rarity's soft, aching rear, and began to massage it. Rarity let out a muffled sigh of pleasure. This felt absolutely wonderful. Not only did it ease the pain, but she liked other ponies rubbing her butt with their hooves - especially Rainbow Dash!

About four minutes in, Rarity accidentally farted in Rainbow's face. She blushed. It wasn't like her to fart so loudly, but Rainbow wouldn't remember it.

A minute later, Rainbow paused, pressed her butt against Rarity's, and let out a loud, deep-pitched fart.

BBBBBBBRRRRRRRRRRRRAAAAAAAAAAP!

Rarity loved this feeling as well. She had never experienced it, though she had played around with it with Twilight and Pinkie Pie.

Rainbow immediately went back to rubbing Rarity's butt for another five minutes. Then, she pressed her head against Rarity's tush. It had always been one of Rarity's biggest fantasies to have Rainbow Dash do this, but she wasn't sure she ever would have done it without hypnosis.

After five minutes, Rainbow Dash removed her head from Rarity's butt and kissed it just as Rarity had done to her. Rarity let out a muffled squeal of pleasure. Then, after farting on Rarity the same way as before, Rainbow started licking Rarity's butt again, without removing her panties this time. Rarity wasn't sure which she liked better, so she decided she'd get an equal share of both in the future.

After five more minutes of licking, Rainbow Dash farted on Rarity's butt again, and then sat down in front of her.

By now Rarity needed to pee more than ever. Would Rainbow Dash pee before her? She looked fine now, but she had drank a lot more so the second wave of pee should come soon.

Soon, Rainbow started fidgeting where she sat. Rarity would be fidgeting by now too, except she couldn't move, so all she did was yell frantically through her gag. She knew it wouldn't do anything, but it was all part of her fantasy.

"MMMMMMHHH! MMMMMPPPPPPHHHH! NNNNNNGGGGHHHH!"

Soon, Rainbow stood above Rarity and peed on her again. Rarity loved it, and it made her leak a little into her panties.

Once Rainbow finished peeing, she farted on Rarity's rear again.

Rarity held it in for another hour. She didn't want to voluntarily let go even now. She never suspected she could hold it this long.

Finally, Rarity peed. Her frantic muffled cries stopped and she let out one of relief as she soaked her already-wet panties and dress, forming a big puddle under her. She peed for about a minute, and stopped. Her heart was racing. This was it. She had wet herself while immobile. This was another of her fantasies.

Rainbow Dash untied Rarity, for she had followed all her instructions.

I want you to pull my panties back up, and lick my hooves for two minutes each hoof. Then slap my rear twenty times with your hooves, then the flyswatter. Then take that whip that's hanging on the wall and whip it ten times. After that, massage it for ten minutes. Then, press your head against it for five. Then, kiss it, then lick it for another five minutes. WITHOUT pulling my panties down this time. Whenever you feel an urge to fart, put your rear against mine and fart as many times as you want. Then wait until a.) you have to pee again and give me another golden shower, and b.) I pee myself. In case you can't tell, for any reason, like if I pee at the same time as you: When I get desperate, I will be trying to speak through my gag, and I will stop once I wet my panties. Once both of us have peed after this, un-gag and untie me.

Once Rarity was back on her hooves, she had Rainbow Dash lay down on her back and tied her in the same position, and then began to lick her hooves.

This was ticklish to Rainbow Dash as well, and she laughed really hard. Rarity licked each hoof for five minutes, starting with the front hooves this time. Once she started licking the back hooves, Rainbow laughed so hard she peed herself, as the last of the cider had gone through her in the past hour.

Then, Rarity clapped her hooves three times, deciding it would be a little fun to let Rainbow wake up in this position.

Rainbow Dash looked around. "Hey, why am I... Hahaha, I knew you'd do something like this, Rares!" She realized she was wearing a pair of wet panties. "Did you have me give you a golden shower too?" She must have, for Rarity was completely soaked. She also realized her butt was sore, and had a good idea of what else Rarity must have done to her.

"I'll tell you all about it, and THEN I'll untie you," said Rarity. "And then, hypnotize me again and do exactly what you did the first time."

Author's Note

Once again, by request. My fetish side will be REALLY tired after this and might need to rest for a few days, maybe even a week, after this.

A few of the extra ones I came up with, while the bondage, hooves, and whip were requested. I hope it isn't a disappointment to anyone curious as to Rarity's dark fantasies about Rainbow Dash.