The voracious asshole undulated around Mark's face, gorging on his tongue in a deep wet kiss. It felt unreal that this twitching monster was Sarah's poophole, clenching violently as she masturbated. Mark swallowed some more anal fluids into his throat, tasting the delicious nectar of her pussy juices mixed within. Jacking off, he gripped his turgid penis harder in his hand, feeling his cock throb with pleasure. Buckets of sweat ran down his brow, all but lost in the plethora of sticky fluids coming from the giantess. Her anal ring trembled as she let out a mighty moan, squeezing its puffy wrinkles around Mark's jaw.
Her slutty asshole was definitely becoming more loose as time went on, but the tiny boy could tell that its inner ring was still clamped shut. Hot bubbling gurgles stirred from within, closing in on his location. He knew her body was still trying to prevent more gas from leaking out, but he wanted more. As he licked and prodded with his tongue the gurgles grew louder, increasing to such a magnitude that it started to make vibrations shake through her sphincter. Mark had no idea the size of what was coming, a massive load was moving down his classmates colon. It was both gaseous and solid, and many times bigger than him. The size made Sarah's bowels expand with pressure, and a heaviness filled her butt.
Suddenly Sarah hit a sweet spot in her pussy. Her muscles clamped down and sucked on her fingers. At the same time her ass squeezed down too, compressing around the steamy balloon of pressure inside her bowels. Huge whirlwinds of gas came swirling past her sluggish load of shit and shot out her hole. The anus retracted around Mark's head, disengaging from their sloppy wet kiss for a moment to blast him with an explosion of shitty fumes. Sarah's meaty fart ripped straight down his throat, coating his insides with a thick layer of girl gas. The rank release was sweltering and potent, creating a rancid humid environment within her crack. Sarah's ass cheek split apart to let the fart spurt through, making a loud trumpeting sound as it came out.
"Nngh! ... Oh, that was a loud one, heh heh." the giantess said.
Sarah was taken aback by the bubbly fart in the middle of her masturbation. It was so big and loud as it fluttered through her butt cheeks, she didn't know she had that much gas left in her. Being by herself she just giggled at the size of it, but at the same time it also kind of turned her on. The foulness of doing such a deed while fingering herself, it made her double down on her pussy, jamming her fingers into her snatch even harder. Sexy moans escaped her lips. Warm pools of juices moistened her panties, making them soggy. She didn't care, she didn't want to think about her clothes or anything else until she had finally cum.
Mark gasped, with a puff of hot farts exiting his mouth. Sarah's wafting odor had become more intense than before, the concentration of her gas had reached dizzying degrees. The shrunken boy inhaled deeply, sucking in her moist fumes through his nostrils. His eyes rolled back into his head, it smelled so gross and meaty that he nearly came a second time. Just the idea that the cute Sarah's perfect ass let out a stench as rotten as this... it was unbelievably sexy. Her anal perfume latched onto the roof of his mouth, he could taste just how spicy it was. Mark took another long inhale of the smell into his lungs before diving back into her hole.
Even more determined now he wriggled his skull inwards, pushing apart the wrinkles of her anus with his forehead. Gooey threads of slime ran through his hair, warm and drooling down to his scalp. Sarah's shithole squeezed back, but after the fart it seemed a lot more accepting of his movements. The docile hole let him force his face deeper, practically widening for him as he did so. It was the hottest thing ever, and Mark could only think of inserting himself further. Soon he reached past the outer wrinkles of the girls anus, past the stained brown bands of skin. Her slimy pink inner anus laid before him in the darkness, throbbing with anticipation.
Sarah suddenly let out a high-pitched moan above, and her nethers clenched. The widening anus contracted around Mark's head, shrinking the features of his face into her wrinkles. His whole skull was locked in the pulsating embrace of her asshole and he absolutely loved it. In the heat of his passion he jabbed his tongue outwards, carving it through the stiff anal folds to taste more of her ass grime. Sarah continued to finger her pussy, frothy slime splashing from the entrance. Her muscles clenched in a fever, she was even more horny now, unaware that the tiny buzz in her ass was actually Mark's twisting head. The tiny man thrust his face into her shithole like it was a cotton swab, rubbing it all over the greasy clenching bands of flesh. The hot grueling stench made him light-headed, but there was no way he would stop himself now.
Sarah was panting at this point, moaning faster and faster between sharp breaths. Saliva collected in her mouth, getting thicker and more viscous as clouds of pleasure filled her head. Her eyes were focused on the video on her phone, watching intently as she got herself off. She gave her clit a good squeeze, while jamming her fingers in all the way inside her pussy to finally achieve orgasm. A hoarse scream leap from her throat, announcing to the bedroom that she was cumming. Her cunt seized up rapidly, clamping down on her fingers with a frantic rhythm. Down below, Mark felt the passionate embrace of her asshole kick into overdrive. The hard loving squeezes turned into punishing iron stomps, pounding his head repeatedly like a jackhammer.
"She's cumming" he thought, the simple note was all he could think of through the blinding pain.
Even though his head was being crushed inside a powerful vicegrip his boner was still rock hard. His goddess was cumming on him, using his tiny body as an ass toy for her giant butt. She didn't know he was there, but her asshole loved the feeling of crunching down on his minuscule skull. The anal wrinkles hungrily contracted on him like a giant beastly maw, chewing his head ferociously until it was satisfied. Sarah felt a hard tingle resonate from her butthole, adding to the delightful orgasmic waves of pleasure. Her hips bucked on their own, raising higher and higher until they lifted off the bedspread and then came crashing down. The girl finally let out a hot gasp after what felt like forever, as she rolled her body over on its side.
Her butthole relinquished its incredible grip on Mark's head, slowly yawning open once more. Mark coughed and wheezed, feeling scrunched up and mangled like a half-deflated beach ball. His ears were ringing from the aftershock of such an intense beating, but he still felt more horny than ever. His classmate's giant twitching hole quivered around him, making faint spasms in the afterglow of her orgasm.
Her muscles relaxed, almost a little too much, as her asshole started to gape around Mark's head. With nothing to hold it back, a slow hissing fart was expelled from her sphincter, as quiet as a sigh. The release was a small loosening of pressure for her, but for Mark it was a gushing inferno of gas. Her stench was thicker than ever before, ripe with the taste of shit. Mark couldn't take it any more. His dick exploded from pleasure, spurting cum all over his waist. The heat of the fart was stifling, a muggy rancid odor so thick it was practically fog. Sarah's shit was inches away from exiting her hole now, if her asshole relaxed open any wider now the turtlehead would start peeking out. Mark heard the wet crinkle of her feces inside, shifting as the blazing hot gas blew around it. Eyes watering, Mark winced and arched his back, riding out the rest of his orgasm.
As the tail end of her fart trailed off, Mark was left slumped over. He felt immensely satisfied, like in one heated session of Sarah farting and masturbating he had died and gone to heaven. This girls ass was the best of all time, he felt like he wanted to live between her perfect butt cheeks forever. Her anal muscles twitched, letting the shit stored inside lurch forward once more. It was close, close enough for her body to know that she was about to dump. Her once-gaping hole contracted, squeezing backwards into a tight seal and taking Mark's head with it.
Once more his whole head was constricted by the grip of her anus, this time it was being used as a stopper to prevent her shit from coming out. Sarah felt this, her poop was near the exit of her bowels and she didn't have much time left. All those stinky farts from where she was masturbating had come to an end, and now she needed to drop some serious cable. Lazily she rolled off her bed, still in a mess from her orgasm, and marched towards her bedroom-connected bathroom.
Mark could barely collect short breaths of air through the wrinkles of her asshole. The giant flesh aperture was closed tight and not letting him slip out. As Sarah's giant body walked, his neck-down dangled between her cheeks, swinging in her ass halves with every step. After a few more steps she had reached her destination and stopped. Mark didn't know if he was ready for this.