It was finally happening. Sarah was going to fart all over Mark's tiny body, with no idea he was there. The tiny man could hardly contain his excitement, he had been waiting all day for this. His school crush, her ass, her massive curvaceous butt was ready to let loose a chain of burrito-fueled farts on him. The thought alone was enough to make him hard, if he hadn't already been hard from sniffing her anus for the past several hours.

In the musky darkness the giant hole twitched in front of him, clearly feeling some disturbance as Sarah's ass slowly filled with gas. Her inner chamber croaked as its walls expanded to fit the bubbles of flatus, the sound became muffled through the layers of fat and muscle holding it in. Mark heard the churning bowels groan around him, the volume growing louder with each passing second. Sarah's anus started to pucker, its wrinkled folds flowered outwards before a hard clench pulled them back in. Her body was subconsciously squeezing her anal orifice, keeping it shut to prevent the escape of gas. The great hole trembled as it squished its oily bands of skin together, it could only hold back for so long.

Another huge bubble of stink entered the schoolgirl's ass. The compounding mass of air pushed back against her butthole, bending the round pucker outwards. Mark could only make out some of it in the darkness but he could see his crush's anus bulging towards him again. Her muscles pulled back once more, straining to hold the pressure inside, but before long the anus started to balloon outwards again. Sarah's massive asshole was pumping in and out, hardly able to contain her farts. Mark salivated, ready to accept her monstrous gassy release.

"C'mon Sarah... Let it out. Let your perfect ass rip, right in my face." he begged.

After her sphincter had clenched enough times on its own Sarah started to take notice. The feeling in her gut was heavy and bloated, causing her a small twinge of discomfort. She felt the fart knocking at her backdoor, warming the inner rim of her asshole. It was going to be a big one, she could tell. Sarah gave a smile, she had let out a couple stealthy stinkers in the library today, but this one was going to be huge in comparison. Knowing she was alone in her room, she purposely pushed with her anal muscles, to hear the loud and boisterous noise that came out.

The anus split in front of Mark's face, unleashing a powerful blow of deafening gas. Huge bubbles of potent air came sputtering out Sarah's asshole, covering the tiny boy in her patented shitty stench. Her giant cheeks rumbled around him in a fury as the humid anal steam sought to escape her rump. The entirety of her backside was trembling in a fierce storm of sharp vibrations, the rank fart rang out for several seconds, spewing its meaty gases straight at Mark's head. Her anus was practically screaming at him, warbling its slimy wrinkles together at incredibly high speeds as the fart was pushed through. A faint spray of wet mist was splattered into the boy's head, coating his lips in the slick moist air that had been entombed inside his friends shithole.

Mark practically drank the foul air into his body, delighting himself on the divine taste of Sarah's fart. It was so hot and stinky, yet so pure, coming straight from the source. The smell was awful, it was rife with the odor of her colon, but he couldn't stop himself from breathing it. Never did he think gas could be so delicious. This air had been cooking inside Sarah's wonderful sexy ass for hours, festering in the most gruesome place of her body, and yet she pushed it out so playfully. He could hear her sweet voice outside, giggling to herself from how noisy her butt was.

"Whoa! That was a big one, hee hee!" she said to herself, with a hint of pride.

Looking away from her book for a moment Sarah peeked over her shoulder at her ass. The back of her panties felt really warm now, and she could catch a whiff of her deed. It was stinkier than she expected, but she'd smelled worse. Using her hand she pulled back at one of her butt cheeks, lifting it up from the other one. Under the soft material of her clothing she flexed her hole, pushing it to release another brutish fart. The heavy wind shot out of her anus and slammed Mark right in the face. With her ass now spread, her leggings and panties rode up her crack and pushed Mark directly against her hole. The material acted as a firm wall, keeping him snug in place as the fart exploded on top of him.

Sarah's asshole let out a mighty gust of rancid air, pouring the smell of her bowels all over Mark, and spreading it across her room. Her anus vibrated against his body, battering his head and chest with its wrinkles like they were a punching bag. Hot slews of putrid gas slapped against his skin, the taste of her deep inner colon stained into his very pores. Mark could barely let out a whimper, but it was one of pure joy. His dick was so hard right now he could cum at any second. The sweltering fart fumes were effecting his brain, making him feel delirious with heightened arousal. This was easily the hottest thing he'd ever experienced in his life and it was only getting better as Sarah let out more farts. Her shithole flexed again, pinching his nose before erupting with another giant stinky fart.

"Aaaaaaaaahhhh... that one felt really good." the giant teenage girl sighed with relief.

Her butt grumbled with disagreement, the sound of more bubbles passing through her system was audible. That yummy burrito was to thank for all these farts. It had broken up inside her body and filled her to the brim with hot steamy gas. The smell was thick and potent, making her clothes reek of shit. She was having fun with it though, because as another fart was ready to exit her bum, Sarah grunted and let it come spurting out. The sound it made was funny and she laughed out loud from how uncouth it was.

Mark dared to have his mouth open for that one. The giant girls thick anal breath filled his throat and lungs and the rest of it came overflowing from his jaws. Closing his lips he held her rancid scent inside him like a hit from a bong, letting it permeate through his body. It was amazing, such depravity was driving him over the edge. Sarah's sexy pucker undulated, rubbing against his face as it groaned with more gas. Sticky threads of slime and juices that had been expelled with her farts were slathered all over his mouth and cheeks. Mark licked her greasy anal folds back, happy to eat her pungent mucus.

He began to strip off his clothes. Up until now he had tried to hold back as Sarah's butt did its thing but he couldn't stop his urges any more. He knew it was wrong, using his friends ass to masturbate when she was unaware was a terrible thing to do, but his dick was throbbing so much that it was painful. Her farts were too much for him to handle, the gigantic eruptions of flatulence had overwhelmed his senses. After getting his pants unbuckled Mark started to pull them down when at that same moment Sarah let go of her ass cheek. The humongous lump of booty meat slammed down on top of the tiny man, squashing him flat. Sarah giggled as her butt cheeks wobbled together and then let out a chain of droning farts.

One after another the sequential blasts of air pounded into Mark. Her wedgie kept him nestled right against her hole as she let it out, ensuring his body took the farts head-on. The anus vibrated viciously, working extra hard to let the sweltering payload of gas come fluttering out her butt cheeks. Just as one fart would end the next would begin, enrapturing Mark in a muggy sauna of anal bliss. The gas roared noisily from Sarah's rear end, making loud bassy sounds much to her amusement. Mark nearly drowned in the unending torrent of farts, by the end of the chain he was even left gasping for air.

Once the rapid-fire assault of farts came to an end things went calm for a moment. Distant gurgling sounds told Mark that the fun wasn't over just yet, but there was a lull. A sharp bang rang out and the ass jerked around. Sarah had just slapped her juicy behind, teasing the round booty for her own pleasure.

"Mmmmh, yeah..." she groaned, praising her butt.

Mark used this opportunity to fully get his dick out, finally pulling down the rest of his pants. With his classmates intoxicating fecal odor all around him he started stroking himself then and there. He leaned in closer to her asshole, pressing his cheek against the center of her pulsating orifice. It was red hot and reeked of her bowels scent, causing him to breathe heavily. His cock was fully stiff and throbbing, ready to fire at any moment. Luckily, so was her asshole.

Sarah squeezed another girthy bubble of gas through her rectum, unloading a massive roaring fart onto Mark's head. The blast went off like a hurricane, blowing back his hair and deafening his ears. Hot swirling winds were forced up his nose straight from her bowels, the ungodly smell of her flatulence made him cum instantly. Mark was sent in to a euphoric orgasm, twitching and rolling his eyes back into his head, all the while Sarah's huge fart droned on. Visions of his goddess filled his thoughts. Her pretty face, her smile, how great her ass looked at school when she wore leggings, her cute laugh, her asshole, the way her cheeks moved when she walked, when she bent over, her smell, her ass, her farts! Her farting ass! Her huge farting ass! Her ass was farting on him! Her giant sexy asshole was blasting him with a monstrous smelly fart! He couldn't take it!

...

When he came back to his senses he was left basking in the afterglow of her fart. The thick anal fumes still wafted around him, stinging his nose. His seed had splattered the rim of Sarah's hole but most of it had been blown away in the chaos. With his tongue he licked her anal folds, lazily wiping the already moist and oily skin with his saliva.