When Naark's sister decided to invite him to a threesome with another mare, this was hardly what he had in mind at all. When the orange pegasus originally showed up, he figured that he'd be in a much more dominant position, over either girl. But instead, he found himself strapped down in bondage gear by his own sister. She was his identical twin, same mane and everything... who held him from behind so he couldn't squirm too much. "Hmmmph, hmmph!" Naark struggled, shaking his head and trying to yell out in disapproval, but the ball gag lodged into his snout kept him from doing so. In front of him stood a green alicorn, swishing her behind from side to side. "Hehe~! Are you gonna do it now?" She smirked, giving both orange ponies behind her a good view of her ass. "Just a minute, Borealis. I'm getting the fastening up just a few more straps..." The sister teased, giving her brother a nice slap on the ass. He yelp. "Cheer up, bro! Once this is over, she'll let you right back out... all nice and smooth~" She teased, whispering directly into his ear. Naark couldn't take his eyes off the pucker swishing about directly in front of his face. "Okay Borry, get ready!"

	He couldn't tear his eyes off the lovely alicorn in front of him... He only wished that he could be getting in that ass in a different context. How it jiggled with every slight movement, and her lovely striped socks tied it all together for him. But his sister noticed his interest, and decided that he was due for a closer look. SHLRRRRRRRRKKKKTT!! Borealis gasped, her hind-hooves quivering as her pucker was instantly stuffed with the head of the orange stallion. He kicked and whined, instantly finding himself in an exceedingly more disgusting environment the moment his head squeezed through that hole of his. The smell was the strongest manure he'd ever experienced, and his head was smothered in the stuff too. And he could only get deeper... His sister mounted him behind, something that he could feel but not see... And grinding up his leg was... a horsecock? The orange pegasus mare came prepared... Hanging between her legs was a very accurate strap-on, down to the plunger tube one could squeeze to cum. Positioning it correctly, Naark could suddenly feel something pressing up against his backdoor. This couldn't be good...

	His sister pressed her hooves against his behind, with one good slam of the hips against his behind. Naark could've screamed if it wasn't for the ball gag.  His ass was stuffed with a good length of horsecock already, forcing it as far in as it could go. Once the false cock was balls deep in stallion-butt, she began to thrust and thrust and thrust. "Hngggg, get in there, assfood~!" She laughed, teasing as she crammed the cock deeper into his ass each time. Naark was between crying and moaning, stretched so far from her sister as his head was buried deeper and deeper in alicorn bowels... The predator's anal walls rippled with surges of pleasure, leading to the girl to moan with glee with each thrust. Naark's sister was fucking him directly into her ass! "Ohhh~ T-thank you so much for the meal~" Borealis moaned, pressing her ass back against the stallion filling her behind. With every second that passes, the mean vanishes deeper and deeper inside that plush hole... His neck, front hooves, chest, and gut have all been crammed into the mare already, with only his back hooves still kicking. Plus, his shaft was also still hanging out of the hole, throbbing greatly with each thrust... Whether I wanted this or not, he was getting quite excited from all the stimulation.

	"Hnnnnggg... GAH!" The sister groans, slamming her fake cock into the stallion one last time. This was enough to send him over the edge, and she knew it. An eruption of fluids splatter out of the tip of his shaft, coating the floor below him in a sticky white. Following this climax, it would go limp and drippy enough to be stuffed in easily. With her brother's climax, the feeder decides to as well, giving the plunger a good squeeze to send a rush of fake cum up her sibling's ass. Pulling up closer to the green pony's butt, she rams Naark a few more times. Along with his cock, Naark's legs were also limp now, with only the occasional convulsion of stimulation from his back end. Thus, it was much easier to get the last of him inside of the marebutt, shoving with her hooves a bit until giving him one final thrust. And just like that, there were only the two mares. The stallion was now smothered in muck inside of the green one, against his will. With all that bondage gear on him, he could hardly struggle. And with all the mareshit mucking up his fur from those bowels, he couldn't tell if the ball gag was a blessing or a curse. But knowing his current location, and hearing the predator's body gurgle around him, he knew he wished to yell as loud as he could. Not like anyone would help him, especially not his sister.

	"Now that my brother's ready to bake in that fudge oven of yours, do you feel like...?" The orange pegasus smirks, walking around to look at the satisfied Borealis. The powerful predator seemed very happy to take in another snack through her backdoor, a bulge hanging down from her lower body. He wasn't even in that stomach of hers, and he already seemed to be gurgling a little bit in there... "Absolutely!" She giggled, already lying down on her side with an inviting view for the pegasus. Her pussy was already dripping a bit... In fact, both of them were quite aroused after what just took place. Thus, the two formed a sixty-nine on the floor. Following a few licks, both of them were muzzle deep in mare heat in no time. One would tease the other's clit every now and then, causing the other to gasp and shudder in reaction. Naark could still be seen struggling inside of the green pony's bowels, desperately trying to escape in some way. But something was starting to feel strange... It was hard to see in such a squeezing, hot, dark prison of alicorn bowels, but he could swear that something was starting to change him... Once he couldn't feel his back hooves, he realized that he was quickly being turned to manure. "HMMMMPH! MMMMPHH!!" The orange pony screams in terror, trying anything in his ability to escape. But it was already too late...

	"U-unghhh! Squirm all you want, mare manure..." Borealis taunts, reaching down with a hoof to press down in the bulge in her bowels. It was getting pretty loud down there, with both the struggles of her meal inside and the sounds of her own ass digesting him. She didn't even have to get him all the way into her stomach to accomplish this... BLRBLRRBLRGLOORRP! Inside the alicorn, Naark found himself petrified with fear as the bowel walls rub against him, more and more of his body being turned to the waste surrounding him with every passing minute. He tried to yell as loud as he could, but there was nothing he could do to even make his cries for help escape her bowels. The two remaining females merely continue slurping at each other's clits, causing both of them to grunt and moan with shivers of pleasure. This would continue until both climax, juices coating both muzzles after the fact. Now, the bulge inside the predator's bowels was rounding out, getting noisier and noisier. There wasn't much left of Naark in there anymore. Well, besides what was bound to come out soon...

	Naark kept trying to fight back, whimpering against the walls separating him from the outside world, but the effects the predator's bowels were having on him kept him from getting any escape. He couldn't hardly feel his back and even belly anymore, all being converted into mare muck rather quickly. And it hardly stopped there, either... With more gurgles shaking the body, Naark felt his conscious begin to slip away as the filthy digestion process overtakes his head. Following this process, there was hardly anything that would make it seem like Naark was a stallion before this. Well, except for the bones embedded in the mess... After being gurgled up, the orange stallion finally said something to break his silence. PFFFLRRRRRBBBTT!! A vibration of gas sputters out of the alicorn, right in the face of Naark's sister. "I think I'm finished with your brother, now~"

	"I'll say." The pegasus rolls her eyes, pulling out of Borry's pussy and taking a few steps back. This was the part she was waiting for the most, giggling as she reaches over to grab her smartphone for recording purposes. Squatting down, the alicorn flicks her tail to the side in order to give the camera the best view possible for what she did to the stallion. "This is going to feel great..." She purred, ponut twitching for a moment before finally spreading wide open to let out the meal residing inside. A fart carrying many orange feathers and bits of hair or fur rumbles out of it first, followed by a log stretching her ass rather wide and causing Borry to grunt. The sister laughs, walking around to get the footage of it all at a nice angle... Sloppy mareshit begins to pile onto the floor behind her, embedded with chips of crunched bone and the occasional bondage strap slipping out of her to join the mess. It splatters out with pudding-like consistency, covering the floor between her hooves with Naark's former self. Suddenly, the flow of waste is blocked up by something gurgling in the predator's bowels. "F-fuck...!" Borealis grunts, pressing down on it with a hoof until she could force it out. Her tailhole stretches especially wide to dump out a partially broken skull, ball gag still around it, as it's dumped out onto the pile like a cherry on top. At least it would be, if it wasn't for what it freed up...

	The blockage being removed from her bowels caused an onslaught of pent-up manure to tear through her bowels, partially burying the skull under its mass. The chunky slop barrels out of her body, raising up past her knees in a fashion filthy enough to make even the sister recording blush. "H-heh~ I don't think my body took in ANY of him... Is your brother always this good of a fuck and dump?" The alicorn smirked, the last loaf of waste finally cutting off and draping itself over the mess she left on the floor. That was all Naark was now... An unsightly load of mareshit piled up onto the floor with only a few signs to tell that it was once him. PFFFFRRRRPPPT!! Borry smirked, one last fanfare of flatulence being his final sendoff. "Oh, he felt so great to dump off~ I'm going to go wipe myself off now, you can do whatever you want with your brother, there..." She teased, slipping out of the room to go and get the last of Naark off her ass. Knowing that she was alone with the pile of shit the mare left behind, the orange pegasus smirks with an idea...

	She sets the smartphone aside for a moment, trying to get in a spot where she can keep recording without holding it. The sister positions herself over the mess on the floor, heat still rising off of it fresh from inside of Borealis...  Then, purring, she jams her hips forward and forces the strap-on into the manure. The shaft pushes itself through several pounds of shit, pushed up against some parts of bones on the sides as it thrusts in and out of the pile. If Naark could say anything anymore, he'd probably be whimpering. But of course, he was not in a position where he could say anything at all. The orange mare grunts, plowing in and out of him with a variety of filthy splattering noises coming from her efforts as well. "I can't really tell what I'm plowinging into, anymore... I think that's the inside of your ass, but I think you just look like one." She teased the pile, ramming into it a few more times before giving the plunger for her cock a good squeeze. A flood of fluid gushes into the pile, getting it wet with the mare's false ejaculate and puddling onto the floor from the sheer amount. "Huff... Huff... This is the best use for a brother I can think of~"