There was something far more sinister about this minute singularity the forces of Chaldea had come to investigate and resolve this time.  Principal among the strange circumstances that allowed the distortion in history to form was the unnaturally potent concentration of curses and malice that contaminated the land, corrupted the forest, and lurked in the lake.  As a result of the nature of these curses, the transient nature of a Servant’s existence became much more tangible and death now carried a permanent consequence to the Heroic Spirits that manifested on the mountain.  Whether this was the intention of the magecraft practiced here or an unforeseen side effect, it was clear from the bits of evidence their initial investigation found that the Mages that once lived on the secluded mountaintop’s main goal had to deal with immortality and immortal beings in some way.

The rules of the Singularity soon became clear to the group that came with Chaldea’s final Master, Fujimaru Ritsuka.  The tropes so prevalent in the horror movie genre were had to ignore, and as night fell, the true dangers emerged from the shadows.

Having barely survived the night and subduing that horror movie villain sent to kill them, the young, Japanese Master and his Servants were quick to decide on a resting order that allowed him to get a decent night’s sleep.  However, the hazy remnants of his dream fading as he slowly woke up had him wishing to return to the comfort of slumber. As he pulled closer the object he was snuggling in his sleep, something tightened around his groin and his finger was inside of something tight, warm, and wet.  Huh?  Did someone sneak into my bed agai…

Recognizing the object in bed with him as humanoid, the small size of the person he was hugging had alarm bells sounding in his head as they wiggled, the tightness around his morning wood increased.  Opening his eyes, he pulled back the covers to see the back of a small head of black hair, tied up in two cute little odango, with streaks of pink in the back pressed against his chest.  The young, Rogue Pseudo-Servant slept sounding as one of his arms wrapped around her slender frame, eliminating any space between them while the other mostly supported her head as she sucked on one of his fingers.  However, if he were merely sharing his bed with the young, innocent girl, that would be bad enough, but looking down her petite body, he could see her white, one-piece, frilled bathing suit with a loose, transparent pink short dress over top it, had been pulled to the side so that his erect member was lodged deep into her pert rear end!

“Wh-What the!”  Freaking out, Ritsuka tried to back away from the girl, but his back was already against the wall and before he could push her away, the Masterless Servant stirred from her slumber.

“Hmm…  Onii-chan?  Morn-huh?”  She turned to look over her shoulder with sleepy eyes, she smiled at him until she registered the discomfort coming from her rear.  “Why’s your thing in my bum?  I know I’m too young for this sort of stuff, and it feels kinda nice, but don’t you know it’s supposed to go in the other one?”  Clenching her bowels around the heated shaft impaling her, a deep blush darkened her cheeks as she wiggled her hips a bit unconsciously.

She was tight and warm and moved like a woman with decades of experience, draining the strength from the dark-haired Mage as he attempted to pull her off of him.  “L-Lily…  N-No, it’s not… d-don’t move l-like that…”  His body seizing up in pleasure, he unintentionally curled around her as she toyed with him.  “P-Please… wait.”

Smiling an innocent, devious smile seeing the look on his face and hearing the pleasure in his voice, the loli Servant rolled him over on his back and stood over him, holding her bathing suit to the side as she went to re-insert him into her tingling bum.  “Onii-chan, does it hurt?  It looks so big and swollen and painful.  But don’t worry, it’s my duty to assist those in need.”  Wiggling her but on the tip of his member, she watched and waited for him to do something.  His arousal was evident, but he was conflicted for obvious reasons.

“Lily… I…  No, s-stop.  This isn’t…”  His reason winning out against his lust, Ritsuka tried to sit up and get the strangely salacious girl off of him, only for her to push him back down effortlessly with one hand.  It wasn’t like he didn’t resist her though, the young Master had every intention and used all his strength to escape from her, but the young Servant hopelessly outclassed him in strength.

“It’s alright, Master-onii-chan.”  The black and pink-haired girl said, slowly applying more pressure on his dick until the head slipped back inside of her.  “Just let Lily make you feel better.”  Leaning down, she licked her lips as she brought them to his, her small, thin tongue dancing across his.  The young man’s resistance melted away as she dipped her hips down, taking his full length up her rear, and then she just held it there.  Sitting up, Ritsuka’s lust-addled face made her feel warm and fuzzy as she poked at the bulge in her stomach his manhood made.  “Delicious!  You taste so sweet, Onii-chan.”  Raising and lowering herself repeatedly, the young girl’s heart was pounding as nostalgia began to dictate her actions.

And Ritsuka, ashamed that he was allowing this to happen, was blown away by her skill.  She was drawing him in, drowning him in pleasure, and pulling him into the deepest depths of his lust.  Even though he knew he couldn’t overpower her to get her to stop, a part of him didn’t want to.  No!  I… I have to resist.  Even if it feels so…

“Hey, Onii-chan?  Lookie, lookie.”  Pulling him from the vestiges of his coherent thoughts, Ritsuka looked at the young girl sitting on his erection with a sweet and innocent, yet seductive and enchanting smile.  Cute and fragile, beautiful and strong, and so pure that it was painfully, irresistibly erotic, her golden eyes seemed to glow as the light of morning lit her from behind.  The three pink vertical ūrm51;ākośa on her forehead and the singular large one flanked with quarter-circular marks to its upper left and lower right on her chest seemed almost luminescent as his eyes lowered to her core to where she was pointing.  Lifting the pink, transparent part of her bathing suit, she sat firmly on his lap and rubbed the part of her belly that was being pushed out by his member.  “Look at how deep you are in me!  I didn’t even know I could fit something so big in me, hee hee.  Here, feel it.  It’s nice and warm.”

Grabbing his hand, Lily pressed it against her stomach and made Ritsuka rub his cockhead.  Through her body, the pressure of his fingers registered on his cock, making him twitch from the odd, new sensation.  I… it feels…  Pressing a bit harder, Ritsuka unconsciously pushed his hips up into her to cause his cock to bulge out a bit more.  Pressing into another sensitive spot, his entire body jerked from how good it felt.

“Ahn~!  O-Onii-chan…”  Tightening her body around his, Lily began to rub her stomach along where his shaft ran and Ritsuka poked and rubbed the head.  “I-If you’re in p-pain…  You c-can let it aaaaaaall~ out in Lily.”  Leaning forward to kiss him again, she raised her hips once more and slammed them back down on the enraptured Magus.

Unable to withstand her anymore, Ritsuka’s body spasmed in orgasm, flooding the young girl’s bowel with his mana-potent seed.  It had been a couple days since they arrived at the Singularity, and he hadn’t had an opportunity to relieve himself, so it was thicker than usual.

“Ahhhnnn~  Onii…!”  As the condensed magical energy entered her body, Lily’s body heated up even more as the seal on her memories was lifted fully.

As he was about to head back to his room after coming from the bathroom late last night, though he was putting up a strong front, she could still sense the fear and unease within him.  It was unlikely that he would have been able to get any proper sleep, so she used a bit of her power over illusions to get him to sleep in her bed.  He was in need of assistance, even if he wouldn’t admit it, and for some reason, she wanted to cuddle up with him too.  But as she laid in bed with him, flashes of the person she was before Yaobikuni inhabited her body slipped through the seal on her mind.  Images of her older form inviting men to her bed and doing grown-up things to them.

Ahhhh~  If only Master’s thing didn’t react to my scent at that moment.  This sweet summer dream could have continued.  She thought as he collapsed onto the bed, and she rested her head on his chest.  Licking her lips, she listened to his heart beating as his cock spewed out a few more spurts of his ejaculate in her rear.  Ufufufu, but how could I possibly hold back after showing me something so splendid, Fujimaru-kun?  Not even my innocent self could resist… if anything, my natural curiosity would make me want to try it all the more.  But now that we started, I… I just…  Slowly sitting up, making sure the young man remained firmly lodged in her rear, Sessyouin smiled in sweet sadism as he looked up at her in shame.  Ara ara.  My, how delicious you look, and being so young means you still have plenty of energy to spare.  If you are going to let me feast, Master…  Raising her hips to start again, Ritsuka didn’t try to stop her.  Instead, he raised his arms to cover his face as he looked away from her, thoroughly ashamed of himself.  “Ufufu, itadakimasu, Master-onii-cha-!”

*Knock, knock, knock*

“Lily-chan?”  As she was about to thoroughly submerge the young man in her lust and debauchery, Sessyouin was stopped as the voice of one of Ritsuka’s Servant’s, Murasaki Shikibu, called to her.  “It’s time to wake up.”

As the Caster-turned-Rider Servant turned the knob slowly to open the door, Ritsuka’s heart rate spiked in panic.  How do I explain this to her?!  How can I explain?  Lily’s on me a-and…  Imagining the look on the generally kind yet clumsy woman turning to utter disdain and disgust was tearing at his heart.  While there were a number of child-like Servants that made advances on him in the past, he was usually able to clear up any misunderstanding with minimal damage to his reputation.  Sure, some might teasingly call him a lolicon, but there was no salvaging this.

“Are you in need of assistance, Master?”  The young girl on his erect member asked in a whisper.  The latch of the door was just released and Murasaki was slowly opening it.  “If you have a wish, I can grant it.  Quick.”  As much as he needed an out for this situation, it would be inconvenient for her summer vacation if the other Servants started looking at her with suspicion too.

Barely processing what Lily said, Ritsuka's mind wasn’t in the right place to make a rational wish.  In his panic and shame, there was only one thing he wanted to do right now.  A wish?  Well, right now I wish I could crawl into a hole, forever.

Sensing his wish, the Rogue Servant used her power of illusion and the extra Mana filling her to fulfill the young man’s wish, making him vanish from under her as she fell slowly onto the bed.

“Oh, you’re already awake.  That’s-hmm?”  Poking her head into the room, the dark-haired, busty author saw how red the Psuedo-Servant’s face was.  “Oh my, are you alright?  You look a bit flushed.”

“Huh?  O-Oh… y-yeah, yeah.  I just… had an exciting dream and woke up early.”  Lily said, turning to better face Murasaki and fixing her swimsuit.  She was also trying to ignore the tingly sensation in her butt, but it was proving very distracting.  “B-But I had something I needed to do today anyway, so I’ll be heading out for a bit.  It might take me a few days, but tell Onii-chan and the others not to worry about me, okay?”  Hopping out of bed, she quickly pulled up the blankets to hide all the evidence of her passionate time with the young Master.

“Of course, I was going to let Master sleep in a bit more given all the excitement from last night, so I’ll make sure to tell him.  Are you sure you’ll be alright by yourself?”

“Hee hee, don’t forget I was in this Singularity before any of you.  I’m not doing anything dangerous though.”  Quickly leaving the room before she did or said anything suspicious, the young girl waved to her.

Well, even if she looks like a child, she’s also Yaobikuni-sama.  Unable to stop the young Rogue Servant, Murasaki merely waved back.  “Very well.  Take care.”

Leaving the cabin that Chaldea had made their temporary base for resolving the Singularity, Lily headed into the woods so that she would be out of sight faster.  Once there was nobody watching her, she looked back at her butt and gently touched it.  She was still a bit sore, but paradoxically, it felt good too.  “Hmm, I guess the seal bigger me put on me didn’t fully come undone.  I can still remember a bit, but a lot of my memories are gone again.”  She said aloud, with an indifferent expression.  “Well, that’s probably better.  I didn’t think inviting Onii-chan into my bed would turn out like this but…”

Focusing on the young man thrashing about in her colon, she peered into the illusion that she gave to him, a pleasant little dream of him curled up in a dark hole, hoping that nobody would even find him.

From his long experience as a Master of hundreds of Servants, Ritsuka was no stranger to being trapped in dreams, illusions, and time loops.  So as the dark, slimy, cum-soaked walls of flesh shook gently as the young girl hiding him away once again began walking, he knew what was coming next.  As much as he wanted to hide what had happened, the overwhelming guilt clutching his heart told him he couldn’t be so selfish.  Whatever the reasons for what he did, he had to be held responsible.

I didn’t mean to…  I couldn’t stop her…  B-But… But I shouldn’t have even…  His thoughts spiraled down as he couldn’t get the thoughts of Lily’s bowel tightly and pleasantly coiling around his erect manhood out of his head, the young Master’s still hardened shaft pressed into his surrounding.  His hips thrusting subtly but uncontrollably into the slick intestinal walls, being trapped with the Rogue Servant’s bowels wasn’t enough of a punishment, and he knew what was coming next.  His heart jumped up into his throat as the young girl dropped her hips a bit, her bowels squeezed tightly around him, pushing him towards the exit.  I’m sorry!  I… I didn’t…

Excreted from her rear with a glob of his semen, Lily made no effort to catch him either, letting him splat on the floor.  The impact always disoriented him, though the pain was reduced thanks to the thick jizz that surrounded him.  However, gallons more flowed from the black and pink-haired girl’s rear, pinning him helplessly as her playful giggling was muted by the dense liquid.  Wiping away the cum coating him, and coughing up what he inadvertently swallowed, his vision was blurry and unfocused as he recovered from the fall.

However, he could still make out the young Servant’s mostly bear rear hovering over him, and the tight hole she expelled him for as his sense returned to him.  Staring up at the cottage roof, there was another person staring at him as Lily said something to the effect of her version of events that resulted in him being in her rear.  Wh-Who is it this time?  First, it was Senpai… th-then Kaoruko, Tomoe… even Illya.  Retaining his remembers from each time events repeated, the looks of disappointment and disgust on his Servants’ faces as Lily outed him hurt worse than any time he fell from her butt.  Every time, Lily showed him to a different Servant, but the hellish dream always ended the same.

“-pai?  S-Senpai?  What are you…?”

N-No…  No, not…  Registering the unmistakable voice of his cute, diligent, pink-haired kouhai, Ritsuka snap his gaze to her as she visibly recoiled from his unsightly state.  Mash!  No, i-it’s not what you thi–

“You w-were… in Lily’s…”  The shock quickly fading, Mash’s soft, gentle features twisted and darkened into a revulsion more potent than when she spoke with Saber Lancelot.  There was no respect, compassion, or sympathy in her eye for him.

“I told you.  Onii-chan crawled into my bed and put his thingy in Lily’s bum.”  Finding the situation as humorous as always, the Rogue Servant plucked Ritsuka up from the puddle of ejaculate and held him up so Mash could get a better look and confirm it was, in fact, her Master.  “And since Lily is a magical girl that makes people's wishes come true, I shrunk Master and shoved him up my bum.  Lily isn’t bullying him.  Onii-chan likes it in there.”  Pointing to his still erect phallus as proof of her statement, she wove a not entirely false narrative of what had happened.

Or rather, from Ritsuka’s perspective, it was the most logical way for her to interpret what had happened.  N-No!  Mash, i-it wasn’t like that!  Trying to speak his case though, more of his cum spilled from his mouth, and Mash simply covered her mouth and turned away from him.

“I can’t believe you, Senpai.”  She said coldly, glaring at him.  “Well, if you like being in Lily’s colon so much, she can just keep you there!  We’ll investigate this Singularity without you.  Enjoy your summer camp in her butt!”  Running off, Mash left him to his fate.

No…  Mash, come back!  Please… I-It’s not…  Hanging limply as his long-time ally and companion left him behind, the young Master stared at the floor in disbelief.  All the other Servants in the previous loops said something similar, but hearing it from Mash stung all the more.  No…  I deserve this…

Turning him around and playfully licking him clean, the black and pink-haired girl smiled gently at him.  “Aww~  Don’t worry, Onii-chan.  Even after all your Servants abandon you, you’ll still have Lily.  Lily will keep you safe and right where you like the most.  Come on, let's get you back in my bum, okay?”

As the only one that offered him kind words and encouragement, Ritsuka could only nod as she lowered him back to her butt.  The cum-dripping, quivering anus eagerly awaited him, and despite his relatively large size compared to it, it sucked him up with ease.

Embracing the undulating intestinal walls, Rituska ground his crotch into the slimy flesh and licked at it affectionately.  Yes…  Th-This is what someone like me deserved…

Leaving him to debase himself for what he had done to her, Lily tightened her bowels around him in a caring embrace.  Despite intending to give him a pleasant dream, he was the one with the most influence over how the events of it played out.  She only kept him in the illusion, nothing more.  He was the one tormenting himself for something she thoroughly enjoyed.  But, if that was the type of dream he wished to have, she’d let him continue.  Unable to escape from her, presented to each of his Servants as they reject and condemn him, leaving only her to accept and embrace him in the end.  There was only so many times his mind would be able to handle it before he broke, but it’s what he wanted.

“...you really don’t know if you want to be punished or rewarded, do you?  I could let Onii-chan out of his illusion and let him experience what it’s really like in my butt.  Hee hee hee, maybe later.  Lily will keep you safe, Master-onii-chan.  This Singularity will resolve itself eventually, and I’ll bring you with me when I leave.  You can live in my bum forever if that’s your wish.”  She said, rubbing her bottom.  Performing a twirl and holding out her magical girl compact, she struck a pose and smiled.  “It’s my duty as a magical girl, after all.  Sowaka, sowaka.”