Two Unicorns one Extra large Hayburger combo meal
"...but... how can you really say you love me, if you won't let me shit on you?"
Starlight pulled herself back, eyes fixed decidedly away from the magician.
"I'm sorry. I... am really struggling to get my head around this. You're saying you... really, really want to... uh... do your business on me?"
Trixie chuckled. "I don't know how many more ways I can say it, Starlight; it's the next logical step in our relationship!"
"It... is?"
"Well of COURSE it is. Besides, I went along with that bizarre little kite roleplay you were so insistent on me doing. It was cute how hard that made you cream."
"Tr-Trixie!" Starlight looked around, making sure there were no other ponies within earshot. She didn't exactly want to appear prude, but this was something a little outside her comfort zone.
Her shoulders sunk with capitulation.
"How... exactly would it, y'know, work? Not that I'm saying I'll do it, but..."
"It's simple, really. I go eat a lunch that's a little bigger than I can manage, and this evening, when I inevitably need to evacuate my great and powerful accumulation, instead of into the toilet bowl, it will be onto your face." Her mouth curled at the edges; a sick, satisfied smirk.
"Can I... think about it?"
Trixie sighed, but relinquished. "Very well. Even if you're not up to it, I can enjoy the results myself."
The implications made Starlight feel a little sick, but still, she allowed the idea to sit in her mind.
The mares went their separate ways; Trixie to buy the largest combo meal Hayburger had on offer, and Starlight to seek some advice from the pony she always knew could help.
"She wants to... sorry... what!?"
"You heard me."
Twilight turned, face rooted with deep concern.
"Well. I have to say, that's new."
"It's... really weird, but I don't want to disappoint her."
The purple alicorn settled down opposite Starlight, raising her teacup to her lips to take another sip.
"Well... it's... safe, I guess. It won't kill you."
"Yeah, but, it's pretty gross!"
"Oh, it's very gross, but that's likely what Trixie finds so sexually fulfilling about it. If you'd like, I have a few books about the nature and root of common and uncommon fetishes. It's a fascinating read." She brought a book floating over to her, the title read 'Working out the kinks: an exhaustive guide to what makes us flick'. She opened to a page. "It's interesting she specifically wants to, ehm, relieve herself, onto you, rather than the other way around. According to this, that often means the pony derives sexual satisfaction from degrading somepony else and putting them in a position where they're lower than them." She looked up, noticing the concerned expression which had spread across Starlight's countenance, "Not that she doesn't love you, of course, in fact, you should probably be flattered it's you she wants to share this fetish with."
"Hm. Well, the way she blatantly goes on about it in public she's not exactly making an attempt to keep it under wraps."
Twilight closed the book, though Starlight noticed she seemed to fold a small dog-ear onto the page which she'd been open on.
"Ultimately, it's your call. It's gross, messy, and demeaning, but it'll make her happy."
"You're right. I guess... I can put up with it just once. For her."
Twilight nodded solemnly. "Let me know how it goes."
She paused, realizing how this came across, "Uhmm! I mean... you don't need to go into details or anything, but let me know if you two work it out. This is a unique friendship problem to say the least."
A few hours later, after working the idea over and over in her head, Starlight headed back to her section of the castle.
"Well, Starlight! How is my favorite- uughh-"
Trixie curled up into a ball, her hooves desperately rubbing her belly in an attempt to soothe it, all it did was let out a disgruntled rumbling noise in response.
"Sorry. Did you come to a decision? I think we're going to have to start... pretty soon..." Her voice tapered into a raspy squeal as another wave of pain washed over her.
"I'll do it!"
"You will!? Oh, Starlight!" With a burst of energy she seemed to find from somewhere, the blue unicorn jumped up and pulled her partner into a hug, though this only seemed to upset her stomach more.
"Uhm... perhaps we could take this to the bathroom? I'm already turtle-heading and I'm not sure how much harder I can... squeeze this in..."
Starlight noticed Trixie's hind legs were both pushed together, her cheeks joining in the middle and concealing the partly-released log that probably sat somewhere between.
The mares hurried to the en suite, where Starlight, instructed by Trixie, sunk to the floor and laid on her back, hooves held up over her chest protectively.
The unicorn paused, her stomach rocking like a storm-bearing ship and emitting a low, curdling gulpy noise.
She brought both hind hooves down either side of Starlight's head, allowed her tail to rise steadily, and finally feeling she was free to let go, did so.
The light brown loaf of excrement appeared from between her cheeks, pressed out with a wet noise and growing longer and longer, hanging down for a moment before breaking off and landing with a moist splat right under Starlight's chin.
Immediately she was assailed with the sharp, overbearing stench of manure. The kind of smell that seemed to strike her most primal senses.
She managed to bear it, though, looking up to see another long, textured log was working its way out from Trixie's rump.
"T-Take it!" She gasped, and pinched it off, letting it fall perfectly over Starlight's face.
The smell hit her even harder.
"Trixie! This smells disgusting!"
"Well, what did you expect? It wasn't gonna smell like roses, was it?" She punctuated this with a dry, pitiless laugh.
Back arching and shoulders lowering, she tried to squeeze more through, her stomach protested again, and instead of something solid, passed out a little short, wet cluster of gas.
"Ooh! That was a wet one, wasn't it? Or... would you like a closer listen?"
Trixie's demeanour had been taken over entirely by her lust; this fantasy that she had doubtless enacted in her head multiple times.
Starlight, remaining silent, aside from a few whines, watched as Trixie's plot lowered down towards her face, legs squatting down and fetlocks pressing lightly into either side of her head.
Another fart dribbled out; wet, spluttery, and immediately potent.
A sharp, raw, vegetal smack that caused Starlight to heave and cough.
"Sorry. My farts are ALWAYS on the stinky side."
Starlight did already know this. Trixie was often not one to bother holding back if she had to pass gas, but she'd never had one directly in her nostrils like this. It burned a little.
Starlight decided that, even if this situation was deeply unpleasant for her, this wasn't about her. It was about Trixie. This was likely the only chance Trixie would get to live out this sick, repulsive fantasy of hers, so, even if it took every ounce of effort she had, why not make it worthwhile?
"Y-You got any more for me?" Starlight managed.
"Hm? You want more already? You like being turned into a mosaic of feces, do you? Oh, Starlight, you dirty little mare. If you want more, you're going to have to really want it."
"I... do. I want to feel... your shit over every inch of my skin."
"Well well well. Is that so? What do you like about it?"
Starlight felt a little wet slobber of something wet and warm against her belly. She looked up to see Trixie's marehood was sopping wet; swollen, almost pulsing, and soaked.
"The smell. The smell that hits me deep. It's disgusting. I want to smell like your shit forever."
Trixie moaned softly, hoof sinking between her legs as she started to massage her pussy.
"Mmh. Well, I guess if you really want more, I'll give you more."
She strained audibly, her ponut puckered and shuddered and eventually distended, opening wide to allow another soft brown tube of solid matter to pass through with a moist crackle.
It curled, twisting over itself before falling beside the previous log. It draped over Starlight's cheek, and was shortly followed by another. This one hit Starlight just below the eye, which she closed. It was bad enough getting this over her face, but she didn't exactly want it in her eyes.
"My, what a huge load I have for you."
"Oh, you call this big? How about you stop giving me these pathetic excuses for turds and show me a stallion-sized log?"
Starlight was a little concerned that all this seemed to be coming to her so naturally, but she could see it was fuelling Trixie's ardent desire. The mare elicited tremulous whimpers and sensual moans.
"O-Oh, Starlight."
Her pussy dribbled onto Starlight's belly again.
Trixie stuck out her rump a little more, reaching the unoccupied hoof back to pull open one of her cheeks.
"Here... comes...."
After a few moments of pushing, Starlight could see another lumpy brown snake emerge, catching the bathroom light and glistening, almost greasy in appearance, as it grew longer and longer, hanging down, but still remaining uncut.
With what seemed like some kind of tricky restriction of her sphincter, Trixie managed to let the single log touch down onto Starlight's chest without breaking it off.
"B-Big enough for you?"
But still, it seemed to remain intact, starting to coil in a little bundle, Trixie kept it coming, adding to the pile, this one single shit that had to be at least a meter long. It was genuinely impressive.
When it finally broke off (it could have probably grown a little longer, but gravity was not on Trixie's side), it fell with a smack over Starlight's face. She was now covered in Trixie's waste. The unrelenting stench was all she could breathe.
Her partner, on the other hand, was enjoying the situation thoroughly, her hoof gliding with a wet smack over her lubricated marehood, her hips started to gyrate.
She had more, though, expelling another three thick, hefty logs that all fell over her pony toilet; Starlight's coat was now more brown than pink.
Then, out of nowhere, a strange desire struck Starlight. It wasn't exactly a desire for herself, but more one for Trixie; something she had told herself with absolution she would not do, but now, in this moment of her partner's climbing sexual arousal, she felt she had to.
"D-Drop one in my mouth."
There was a moment of silence.
"R-Really? Oh, fuck, Starlight, you're filthier than I thought. You’re making my... pussy... burn."
Trixie giggled like a skittish schoolfilly as she continued to soothe that burn, rump reared and ready as it loomed precisely just above Starlight's face.
Her mouth opened wide, tongue lying over her lower lip in anticipation.
Trixie tensed her abdominals as hard as possible, feeling something brew and shift within, slowly easing out more and more; her anus trembled, opened, and allowed the putty-like waste to spread out.
Starlight watched; it dangled, pendulous, and then with a wet snap, it fell into her mouth.
She was overwhelmed by the bitter, disagreeable flavor, but the act of shitting in her marefriend's mouth was enough alone to bring Trixie to a violent, messy climax.
Her legs buckled and her hoof was drenched in a spray of juices; with a shuddering, euphoric sigh her pussy squirted again, splattering over Starlight and filling the air with a high, damp-smelling musk.
The feces sat in Starilght's mouth. A sharp, nutty, almost earthy taste that somehow didn't bring her to vomitting. She spat it out, though the taste remained.
"Oh, Starlight..." Trixie panted, breathless and spent, and pulled her friend up into a hug... even if she was still covered in shit.
The unicorn held the other close, relaxing into her with a sigh.
"Oh, that was amazing. I don't think I've ever had an orgasm so intense in my life."
She pulled away, looking at Staright's shit-stained face.
"What a beautiful little shitmare you are." She cooed, leaning in and planting little kisses all over her sullied complexion.
Tasting her own shit didn't seem to phase Trixie in the slightest, but then, why would it?
"Now..." Starlight began, smiling sheepishly, "I think we could both do with a nice hot shower."
"Naturally." Trixie giggled, "Though... if you don't mind... can I look at you like this for a few moments more? You're so pretty like this... stained with my shit. Perfection itself."
Starlight laughed, but found, strangely, she didn't care so much either. Trixie was happy, so she was happy.