Moana had tied Anna down to train tracks while she was sleeping.

They were hallmates at Georgia University. Freshman. And Anna's fart video had won an award over Moana's.

A huge wave of jealousy had washed over the Polynesian's face as she watched Anna take that trophy.

It wasn't fair. In Moana's video, she had broken plates and ripped a rolling chair in half with her farts.

Anna had been able to play guitar with her flatulence though. Everyone expected Anna to become a fart musician. In fact, Moana did get second prize, so she had confirmed to herself that she would've won had Anna not butted in.

No pun intended.

Moana now regretted that she hadn't gone to Cornell. She had seen this year's classmates of fart majors videos online from there. And gosh were they atrocious!

But Moana had a plan. It didn't matter if Anna was better at making fart videos than her.

After tonight, Anna would be a fart slave.

The redhead's eyes fluttered open. "Where am I?" she asked.

"About to die,"Moana said, spitting on her.

Anna looked to her left and right, as a cold breeze bashed into her face.

"You really brought me out to tie me down to train tracks?"

"Yes, I did," Moana said.

"What did I ever do to you?"

"Stole that trophy from me, that's what," Moana said, a manic gleam in her eye.

She shook her pink-skirted butt above Anna's face.

"Look, you have a very nice butt. I'll kiss it or whatever you want, just come on and untie me."

"I don't want you to just kiss it, I need you to beg to be my butt-slave."

"That's silly," Anna said. "Someone who wins a competition is obviously above you." Moana stepped onto her breast, and pulled down her skirt, revealing her vag. "Right now I'm above you. And I need to pee."

"Not on me, you do-!"

Urine splashed out of the brown girl's urethra, right into Anna's open mouth.

Anna turned her face to the side to spit it out, and Moana jumped off and put back on her discarded high heel. She drove the heel into Anna's cheek. "Anyone who spits out my drink for them deserves to bleed," Moana said, as a drop of red trickled down Anna's cheek.

"Stop being so mean!" Anna said.

"You were the mean one, when you decided to go to the same college as me. That trophy should be mine."

"Excuse me? I didn't even know you before I came to Gerogia U. In fact, I can't say I knew you at all before tonight, considering that you have tied me to TRAIN TRACKS!"

"Look, I failed to get the actual trophy, so you are going to be my trophy instead," Moana said.

"You're just being ridiculous. Now untie me."

"I can't until you swear you'll be my butt slave."

"Absolutely not," Anna said. She struggled against the ropes.

"Maybe some of my stinky fart will change your mind?" Moana asked.

She lowered her butt to the redhead's face.

FFFFFFFFFFFFFFFFFFFWWWWWWWWWWWWWWWWWWWWMMMMMMMMMMMMMMMMMMMLLLLLLLLLLLLLLLLLLLLGGGGGGGGGG

"Oh gosh, those hardboiled eggs don't come out well," Moana remarked.

Ffffffffffffffffffhhhhhhhhhhhhhhhhhhsssssssssssssssssssssssswwwwwwwwwwwwwttttttttttttttttttttttt

Anna was very uncomfortable. Moana clearly had taken a dump recently and not wiped her ass. And now Anna's nose was lodged in her anus, which had streaks of nastiness along its walls.

When Moana stood, after five minutes of farting, Anna started to cry, as she gagged.

And yet, Moana's ass was beautiful, when it wasn't farting on her. In fact during the video presentation, while watching the Polynesian's video, Anna had wished she could smell Moana's farts. Just for a short time.

But this, it was ridiculous.

"Good thing the train doesn't run at night," Anna said, when she finally got the gagging down.

And then they heard it. The distinct sounds of a train shooting down the track.

"You were saying?" Moana said, grinning.

"Oh come on, you can't literally leave me on the tracks to die. You'll have no one to fantasize about farting on."

"If you don't beg me to make you my butt-slave, I'm going to let you die."

"I don't' believe it," Anna said. But she could hear the train roarer nearer.

"Beg!" Moana barked.

"Moana, please."

"You're just begging me to untie you. I'm not going to do it. Beg me to make you a butt-slave."

"But…"

"MY BUTT IS THE ONLY THING THAT MATTERS."

"Well, it's probably too late anyway," Anna said, groaning. "But yes, if it's the only way,I am too young to die,so…yes, Moana,I will be your butt slave."

Moana scratched her leg with her heel. It bled hard.

"I will not give you permission just because you say you will. You have to sound like you REALLY want it."

"Please, Moana, let me be your butt-slave!" Anna shouted.

At this point, the train was so close that Anna was sure she'd die. Well, it was better than having to smell Moana's farts for ages and ages to come.

"Finally, exactly what I wanted to hear!" Moana said with glee.

At that moment, she bent to touch her knees. And farts which sounded like gunshots rang out.

WWWWWWWWWWWWHHHHHHHHHHHHHTTTTTTTTTTTTTTTTTTTTTTT

UUUUUUUUUUUUFFFFFFFFFFFFRRRRRRRRRRRRRRRRRRRRRSSSSSSSSSSSSSSSSSSSSSSSSSSSS

BBBBBBBBBBBBBBBBBBBBBBBBBBBBWWWWWWWWWWWWWWWWWWWWWWWWWMMMMMMMMMMMMMMMMMMMMMMMMMMM

The train came just five feet from Anna, but Moana's farts caused it to explode. All along the myriad freight cars, they turned into ash.

When the deed was done, and Anna gazed in awe at Moana's handiwork. The redhead asked why she hadn't been damaged by the farts.

"It only works on inanimate objects that are moving," Moana said., "I had to roll that plate so many times to shatter it with my fart."

She started to untie Anna, then said, "Also, if you try anything funny, I may not save you next time."

"I just want to know one thing," Anna said., as Moana helped her to a sitting positon. "Will I still be allowed to practice for fart music shows?"

"Of course," Moana said. "I want a fart slave, but I'm not cruel. You can follow your dream, so long as after your shows, you know your place."

Then Moana led Anna back to her car, set her face down in the front seat, and her body along with her legs in the floorboard of the passenger side.

"Now I sit on your face the whole way back to campus and fart. Brace yourself, it's a long drive."

She plopped down.

Jjjjjjjjjjjjjjjjwttttttttttttttttttttsssssssssssssssssssss

"Oh, barbecue ribs, they smell so nasty coming out."

The rest of the car ride, Moana released worse and worse rounds of gas. Anna wished she had married Elsa's butt when the concept was proposed to her. At the time, she had thought that marrying her sister's butt sounded ludicrous.

She had planned to go home during summer and allow Elsa to fart on her more and think about it more seriously.

But it was too late now. She had promised to be Moana's butt slave.

And unfortunately, Moana didn't seem the type who would share.

A week later, Anna was starting to hate Moana's butt. She made a couple of attempts to escape, but the second time was dragged back to the room and given multiple face- slashes with her dom's high heel.

"Running away is forbidden. I won't let you perform in your next concert as punishment."

Anna protested, but Moana sat down on her face and farted.

YYYYYYYYYYYYYYYYYYYYYHHHHHHHHHHHHHHHHHHHHHVVVVVVVVVVVVVVVVVVVVVVVVVVVVVTTTTTTTTTTTTTTTTTTT

It was gross. Anna hated the smell of hardboiled eggs coming out of her mistress' anus.

One day she might bring up the possibility of Moana sharing her with Elsa…but she had doubts that Moana would go for this.

Meanwhile, the farts got stinkier and stinkier, Moana's demands became rougher and rougher.

Anna's regret to not go into floral design with her best friend Rapunzel became more and more powerful as the weeks went on.

But so are the dangers of being a fart major. Girls are warned before they take this option that there are risks involved.

Anna also sorta wish she had made her video less entertaining. She hadn't been allowed to Skype with her sister in months. And that sucked.

She was also beginning to forget what fresh air was like.

But at least Moana's ass was cute. Though what was annoying was that she sometimes put on panties with the image of nerdy boys wearing glasses with their lips puckered while she released gas on Anna.

This was double gross to Anna since she was lesbian. In fact her sister's bouncy breasts were her favorite thing in the world. That's why she hadn't jumped at the chance to be Elsa's butt slave.

Because smelling Elsa's farts would mean not getting to play with those boobs.

Though now Anna had no choice but to take Moana's farts.

And gosh did the Polynesian love her hardboiled eggs.

Worse luck.

Author's Note: Please do not judge me on how Anna is dealt in this story. Anna is my favorite character of all time, but sometimes your favorite character is a sub. Obviously I have to love the dom too for this to work, just saying despite how this story may seem, I actually love Anna way more than Moana, but Moana has worked her way into my heart, so here you go.