Princess Celestia's Living Toilet (Scat)

She's somewhat small, (compared to her sister, that is). She's still quite the curvy mare, but her backside could probably only swallow up your muzzle between her cheeks, and not your entire freaking head, down to the ears.

She looks rather disinterested, but she's looking back at you.

You had been almost unconscious when the princess bestowed upon you the punishment, but the words were starting to chime in the back of your mind.

She had made you Luna's slave as well, for a week. That had been your punishment for disobeying her, during her putrid dump.

You start to whine quietly, looking at Luna with fear in your eyes. This seems to amuse her, as her cold facial expression turns to a subtle, but sadistic smile.

"My sister tells me you are in need of punishment. I am here to help with that. Now, I am by no means as cruel as her, but since granted the opportunity to defile somepony, who has no say in the matter, and since she requested my help specifically, how could a possibly decline."

Celestia let's out a rather adorable chuckle upon hearing her sisters speech. You just sit and whimper. The thought of having done to you twice the torture for a week makes you cry. The only thing that calms you somewhat, is the fact that Luna's size would mean she probably wouldn't dispel quite as much waste, and that she probably wasn't insane enough to not wash her ass in 10.000 years.

Luna nods her head towards the toilet table behind you.

"Strap yourself in."

Reluctantly and whimpering, you walk over the torture device, and lay down with your face right under the leather seat. You fumble to get a hold of the mouth-hooks, but stops when you hear Luna reassuring you that they won't be needed. You try to restrain yourself further, but can't get it to work properly.

"I'm sorry your majesty, I don't know how the bindings work."

You close your eyes, hoping she won't yell at you. She doesn't. The restraining mechanism is strapped on with magic. Your hooves, body, and head are all held tightly in place.

You try to prepare yourself for your third scat filling of the day, but to your surprise, Luna levitates the leather seat away and the piss funnel enters your mouth, it's tip still tasting vaguely like urine.

You are as relieved as you expect Luna is about to be. You are much more prepared for piss than scat. But something seems wrong. As Luna's backside looms over your face, she seems to misplace herself. She isn't holding her vagina properly above the funnel. If she were to pee now, she would miss your mouth completely, and piss all over your chest. You let out a muffled sound as a warning of her misplacement before you are hit by an unsettling thought.

Her anus, which is placed exactly where her marehood should be if she were to piss, let's out a moist splattering fart, leaving a scattered pattern of tiny brown dots all over the funnel. Fuck your life.

A moment later a torrent of vile diarrhea sprays out of the exit in her rump, spilling effortlessly down the drain and into your mouth. You sputter and choke in the disgusting mess. It's the texture of a half done smoothie, and it's taste... Bitter, sour, salty and fecal, with a hint of rotten chicken, and it smells, weirdly, a bit like seafood gone bad.

Celestia is laughing her ass off, watching you being filled with her sisters ass-fudge.

You see the funnel start to fill up. You start drinking. Your stomach turns with every gulp you take. She keeps shitting. Her anus is relentless. You gulp it down as quickly as your tortured mouth can manage. Her anus splutters, scatting out a flurry of chunky shit nuggets, making it more difficult to drink. A thin snakelike log quickly coils out of her rectum amidst her warm, butt-chocolate sauce. You are forced to poke it against the back of your mouth using your tongue, as a slow alternative to chewing, since you can't use your teeth with the funnel in your mouth. You have to do this while still gulping down her foul, liquid shit. You close your eyes. Shortly after her onslaught seizes.

You swallow the remaining contents in your mouth. Finally, the torture ends. That was a lot of diarrhea all at once, yuck.

You open your eyes. You are shocked by what you see. Fuck.

A lump of semi-solid feces has clogged the drain, and above you Luna's muddy fountain still flows vigorously, filling the funnel to the point of overflowing. How Luna could still have that much scat was beyond you. Little did you know that Luna caught wind of Celestia's new slave replacement, and had held herself for a day and a half, hoping she would get to use you.

The fear of Celestia's wrath if the funnel overflows is what pushes you to do what you do next.

You start sucking on the funnel like a straw with all your might. Her log slowly moves downwards. You stop, exhale through your nose. You can see the poop about to overflow. You suck again, and with a plop, the shit-piece falls into your mouth followed by a powerful turrent of her liquid excrement, flowing into your mouth like a waterfall. Like a beer bong, you let your throat open, and the disgusting liquid runs straight down. She stops pooping. You are left with a piece of scat in your mouth that you can't dispose of, as it's too hard to mush with your tongue.

Luna walks away. You let your body go limp, and with her scat still in mouth, you fall asleep.