Author's Note

I'm not dead! In fact, I'm more alive than ever and should be getting stuff out more regularly again. Anyway, this story contains: anal insertion, anal, very large insertion, sudden insertion, female on female urethral tonging, Derpass, portal spells, cold urethral enema, getting hosed in the face, all the way through twice, triplet wincest, and Twilight Spergle having a brilliant idea.
Also, don't judge too harshly, this was written in a couple of hours to the prompt "Roseluck commits tax fraud", courtesy of my friends out back.

Mail Mixup Mishap (large insertion, mild urethral, triplet incest)

The doorbell rang, causing Roseluck’s head to jerk up. “I’ll get it!”

Daisy and Lilly looked up from their breakfast, both taking a moment to admire their sister’s rear as she trotted to the door. Catching each other looking, they wiggled their eyebrows in sync before breaking down giggling.

Unaware of the antics behind her, Roseluck pulled open the door. Opening her mouth to greet the visitor, words failed her as her eyes fell on the wide grey ass pointed her way, tail raised as it wiggled side to side. Derpy was well known around town for having a fantastic ass, as well as poor tail control, but Roseluck had never gotten quite such a good look before, and she had to admit that the dark grey ring winking at her as the owner strained and grunted looked even better up close.

Licking her lips, Roseluck took in the sight as she imagined herself with her face buried between those prodigious grey cheeks, lips wrapped around that inviting pucker as she tried to get her well practiced tongue in there as deep as she could. A slap of straw colored tail as it whipped in her face brought her out of it, blinking away the smarts as the oblivious grey mare spun around.

“Oh sorry Roseluck. I didn’t see you there. I got your package right here though! Did you want me to bring it inside or just leave it here?”

Roseluck looked at the large wooden crate that was far too large to fit through the door. “Here is fine, though it is supposed to go to the greenhouse out back.”

Derpy opened her mouth to offer to help move it the rest of the way, an offer that Roseluck wouldn’t have turned down, but she was interrupted by the toll of the Ponyville clock tower. “Oh no! I’m gonna be late again!” Spinning around again, Derpy galloped off, seeming forgetting her wings.

“Everything okay out there?”

Roseluck took an extra moment to appreciate the retreating plot before calling back, “The package is back! You two want to help move it?”

With the clopping of hooves, the other two joined Roseluck, looking at the formidable wooden crate.

Fifteen minutes of grunting and griping later, the box had been moved into the greenhouse. Pulling the lid off, the three mares looked inside only for Daisy to shriek and Lilly to faint. The contents of the crate, their entire inventory, looked like it had been spilled out at some point and then hastily crammed back in, bits of gravel and a couple of clumps of dirt mixed in with the crushed and ruined flowers. Roseluck was on the verge of joining her two sisters when she noticed something purple mixed in with some of the roses. Something that seemed to move.

Starlight Glimmer watched as Twilight paced excitedly in front of her, though she had to admit to herself that she watched more enthusiastically when Twilight was pacing away. What could she say? Twilight’s new habit of stress eating was really helping to fill out her plot.

Starlight’s plans with no ulterior motive involving a nice large dinner followed by some close anatomical study were interrupted as Twilight stopped with a jolt. “It’s happening! I just felt a cool breeze!”

Starlight raised a quizzical eyebrow, “You sure about it this time?”

“Yes! Though I can’t believe I forgot that any mail delivered to the princess has to go through inspection first. They could have been a little gentler about it though. And they could have done a better job repackaging it. I can still feel something digging into the glans.”

Glancing at the clock, Starlight noticed something peculiar. “Uh, Twilight?”

Prodding Daisy until she stopped shrieking and getting Lilly back onto her hooves, Roseluck pointed at what she’d noticed. “Why is there a dick in the box?”

“And why is it throbbing?”

Reaching forward, Daisy gently picked up the surprisingly long and thick penis. “It’s warm too.”

Noticing the piece of paper stuck to the bottom, Roseluck pulled it off and tried to read it, though the wet flowers had rendered most of it illegible. The only clear piece of writing on it was towards the bottom, “‘For rectal use only.’ Did we somehow end up with one of those really expensive magic dildos?”

Taking the purple dick from Daisy, Lilly wrinkled her nose. “Whatever it is, it’s filthy. Pass me the hose for a second.”

“C-C-COLD!” Twilight’s legs locked up at the sensation of her newly gained sensitive parts getting blasted with cold water, completely missing whatever Starlight was saying as her brain was overloaded with the intense sensations. Just as she was getting used to it, the sensations changed, causing her to shriek again, “No! Don’t spray it there!”

Figuring the outside was clean enough, Lilly held the hose to the tip of the toy, figuring she’d just flush out the cum tube real fast. To her surprise, nothing came out the other end. “Turn up the water a bit, I need more pressure.”

Starlight trotted up to her friend and mentor, her concern tempered by the lewd groans Twilight was letting out, the alicorn’s torso on the ground as her butt waved high in the air, large heavy testicles swaying gently as her clit winked rapidly. Noticing something odd, Starlight used her magic to lift the purple balls out of the way. To her surprise, she watched as the part of Twilight’s stomach right between her hind legs swelled. “Wait, is that your bladd-”

At full capacity, Twilight’s bladder couldn’t hold on anymore, a high-pressure jet of still-cold water spraying out from just above her clit.

Having given up on washing out what apparently wasn’t a cum tube, the three sisters had gone inside, the dildo seeming somehow stiffer than ever.

“Since the note said for rectal use only, I guess that means Roseluck gets first try.”

Roseluck turned to Daisy in surprise. “I thought you loved it when I ate your ass!”

Daisy held up a hoof. “I do love it when you eat my ass, but I’m still not comfortable with the idea of actually putting something up there, and we all know what Lilly likes,”

“Hey!”

“so you get first go, though I don’t understand how a dildo can tell the difference between an asshole and a vagina.”

“I don’t mind getting the first try, but maybe that note was meant to go with a bottle of lube, or maybe the postal service messed up even more and there’s a bottle of suppositories in there too. After I’m done, I will personally stuff it in your cute pussy.”

“Alright.”

“As I eat your ass.”

Pausing for a moment, Daisy smiled. “I’d like that.”

Dragging her eyes off the two butts in front of her, Lilly quietly spoke up. “What about me?”

Looking back, Roseluck shrugged. “Would it even fit?”

Studying the toy in Daisy’s hoof, Lilly slowly nodded. “Probably.”

“We’ll let you have round three then while I eat your ass.”

Daisy gently tossed the dildo on the couch. “Speaking of asses, get yours over here so we can get it warmed up.”

Roseluck happily complied, the two tongues digging into her practiced ponut bringing a goofy look to her face.

“I’m so sorry!”

Pausing her grumbling, Starlight sighed. Wiping her face off one last time with the towel, she shook her head. “It’s fine. I really should have reacted faster.”

Trying to change the subject, and trying to ignore the cold feeling that was still enveloping her lower half, Twilight asked, “So what were you trying to tell me before… you know…”

Looking back up to the clock, Starlight confirmed the time. “Celestia is still in court. She doesn’t get out for another forty-five minutes.”

Twilight’s eyes slowly widened as she digested that info. “Wait, then who has my dick?”

Whipping up a tracking spell to trace the low-level portal spell Starlight had helped cast earlier, she ignored the bright signature attached to the crotch of the mare next to her, focusing instead on the much dimmer signature in the distance. “Wherever it is, it isn’t in Canterlot.”

Pulling her head out from between her twin sister’s plot cheeks, Roseluck looked at the purple dick on the couch next to them. “Oh yeah. We were gonna use the dildo.” She immediately regretted saying anything as her other twin pulled her tongue out of her ass.

Starlight and Twilight trotted through town in the direction of the faint magical signature, though much more slowly than Starlight would have liked.

“I honestly don’t know how stallions run with these.”

Rolling her eyes, Starlight chuckled. “It probably doesn’t help that you made them so big. Those things between your legs are bigger than Big Macintosh’s.”

“They aren’t that big.”

“By a lot. You really need to stop basing things off those smutty fics Rarity keeps lending you.”

After another minute of trotting, Twilight broke the silence. “It doesn’t help that they’re so tingly and sensitive.”

“You did read the side effects of that virility enhancer spell, right?”

“Yes! I just didn’t realize it would be so… intense. Ooh!”

Glancing over at Twilight who had stopped dead in her tracks, Starlight trotted up to her. “What’s wrong?”

“They’re touching it again. I can feel at least two, no make that three tongues licking it.” Shuddering, Twilight looked at Starlight in a panic. “We’ve got to go or I’m not going to make it.”

Having thoroughly soaked the dildo in their combined spit, Lilly and Daisy watched in awe as Roseluck’s tight ponut seemingly effortlessly swallowed something far bigger than seemed possible once again. “I’ll never get tired of watching that.”

Taking the opportunity, Lilly darted in to give the winking clit a suckle, her tongue darting around for a moment before finding her target.

“Whoa there Lilly, slow down just a hair. This dildo isn’t fitting as easily as it looks. It’s, like, porn levels of big.” Grunting, Roseluck could feel the incredibly real sensation of the dildo throbbing within her, growing slightly bigger, though the overwhelming sensation was lessened by the sensation of Lilly’s tongue trying to wiggle into her urethra. “Actually, keep going. You’re doing a wonderful job of keeping my mind off the impossibility of this thing fitting while I adjust.”

Given the go ahead, Lilly dove in with gusto, working to spread her personal favorite hole with the tip of her tongue.

Slowing down after hearing that Roseluck wasn’t taking it as easily as it seemed, Daisy nevertheless continued to push the massive dildo deeper into the tight ring, though she was forced to stop as the medial ring bumped into Roseluck’s already straining ponut.

Starlight was barely walking now, helping Twilight stumble along the road as the purple alicorn shuddered and groaned. “It’s so tight. So warm too.”

Starlight eyed a nearby alley, considering dumping Twilight there and just confronting the thieves themselves. Looking back at the fatassed alicorn she was practically carrying, she dropped the notion, figuring she’d win brownie points by not dumping the mare in her time of need.

Doing her best to relax, Roseluck nodded. “Do it.” Biting her lip almost hard enough to draw blood, she groaned as the thick medial ring finally slipped in, assisted by a pair of tongues slathering it in saliva. “Oh yeeessss! That’s a good stretch.”

Pulling her head back, Daisy looked at the last foot of dildo still hanging out. The last five or so inches were probably even thicker than the ring they had barely been able to squeeze in. “Hope you liked that, cause after about seven or so inches, it gets even thicker.”

Roseluck could only groan, winking powerfully at the thought.

Having resorted to carrying Twilight on her back, Starlight did her best to ignore the princess drooling in her mane as she moaned in her ear. She also did her best to ignore the alicorn’s balls that were lightly slapping against her clit with every step, or the alicorn’s mare juices that were dribbling down to mix with her own. She was getting closer though (in more ways than one), the tracking spell burning a little brighter.

Lilly had a perfect view of the final few inches of the massive dildo as she continued to wriggle her tongue against Roseluck’s urethra. Diligently trying to keep the mare distracted (with no ulterior motive at all), she watched as millimeter after millimeter slid into her sister’s straining butt. Roseluck wouldn’t be able to walk straight for a long while, but the rapid winking of her clit against her chin and the veritable flood of mare juices told her just how much she was enjoying it now.

Deciding to return her focus onto her ‘job’, Lilly began drilling the tip of her tongue against the entrance to Roseluck’s urethra with renewed vigor. Pressing just a little harder than before, she was shocked as it actually slipped in, the years and years of continued gentle assault stretching the hole enough to actually accept her tongue.

Feeling the foreign intrusion, Roseluck tensed up tight, her entire body locking up for a moment.

Daisy felt Roseluck tense as the dildo stopped moving and assumed that she had bottomed it out. Knowing what Roseluck liked, she pressed a little extra hard to stretch things out a bit, and was shocked as Roseluck relaxed at that exact moment, the last inch of dildo sliding in as well as the tip of her hoof just as there was a knock at the door.

Standing outside the door to a modest house, Starlight was about to raise her hoof to knock again, ignoring Twilight’s loudest groan yet before she heard a hurried clattering of hooves on hardwood. Standing back as the door opened, she was greeted by a vaguely familiar mare conspicuously wiping her muzzle.

“Hello, how can I help you?”

“We’re looking for something that was lost in the mail.” Starlight pursed her lips as the mare’s eyes widened.

“Ah. Well. Uh. That was for you? Oh. Um. That’d be right this way?”

As the mare led Starlight through the house, Twilight let out another moan.

“Is she alright?”

“She’ll be fine, now where-oh.”

Starlight could only look on in wonder as she watched a mare pull her hoof out of the third mare’s asshole, the tracking spell pointing exactly at the purple object that was slowly hidden as the mare’s anus did it’s job, closing up tight as she shook in orgasm.

At that exact moment, Twilight groaned, her balls contracting, rubbing up and down Starlight’s slit as she came.

The mare on the couch groaned too, before catching a glimpse of the visitors. Eyes widening at the presence of Royalty, she rolled off the couch onto shaky legs, turning to face them even as her belly visibly swelled. “How can I-” Without warning, her eyes went wide as a veritable fountain of cum erupted from her mouth, spilling all over the floor.

In a panic, Starlight undid the portal spell.

The spell’s safeties did their job, moving things out of the way so that the returning object wouldn’t appear inside another solid object, though Starlight would have preferred the safeties just prevented her from canceling as Twilight’s massive marecock reappeared from throbbing base to massive flare inside her own ass, stretching it beyond its comfortable limits in the blink of an eye. The sudden stretching caused the orgasm that had been building since she helped Twilight cast the genital creation spell last night to rip through her, sending her collapsing to the floor as alicorn cum flooded through her system. Within seconds, she joined the red-maned mare in coughing up cum on the floor, though thankfully Twilight’s orgasm was fading by that point.

Daisy watched as the mare that had barged in coughed up one last blob of cum on the floor, the same cum that was drooling out of both ends of her sister. Confusingly, the Princess was on the mare’s back, and she was moaning and groaning like she had also just cum. Watching the three moaning mares in confusion, she stepped back as Princess Twilight slid off the other mare’s back, over two feet of horsecock pulling out of the lighter colored mare’s ass with a pop. Looking at the strange mare’s massively gaping ass as cum spewed out of it, then at her sister’s lightly gaped ass as cum dribbled out of it, then at the princesses crotch where a massive purple cock throbbed with cum leaking out of it too, it clicked.

“Princess, do I still get my turn with your cock?”