Twin Laboratory (Ilien & Idrien Ksakru) (5)
The lewd, wet sounds of flesh slapping against flesh filled the room.
“Hngh… I love it when you take turns stabbing me… Mmm… Mmm… Both of you are the best toilets…!”
Squelch…! Schluuuck!! Squish!!! Schluuuck!!
Even though the scene was incredibly obscene, Marei paid it no mind. He immediately shoved his cock into Idrien’s tight, puckered anus without hesitation.
Schlup…!
“Hiiih… Th-that place… N-no, wait… Uwaah…! Ah, you’re cumming inside me while pushing in… it’s flooding meee…!”
Idrien thrashed about, but the massive penis forcing its way into her rectum left her completely helpless. She could only tremble violently, clinging tightly to her older sister who had already climaxed pathetically easily beneath her and could no longer control her own body. The young boy’s insertion made her hips quiver uncontrollably.
After being used countless times and thoroughly trained, her anus accepted the cock with only the slightest resistance. It swallowed him easily.
Glurk… Glurk… Schlup… Glurk… Glurk… Schlup…
“Hiiih… Hehehehehe… Hiiit…!”
Of course, “easily” was only in comparison to the very first time. Even though barely a third of his length had entered, her voluptuous body was already panting as if she had reached her limit. Her plump ass shook back and forth nonstop, instinctively trying to pull her master even deeper inside.
Despite being used so many times, her hole only grew tighter and tighter with each thrust. The sensation pleased Marei greatly, and he freely planted his seed deep into the elf professor’s barren womb.
“You said inside… but you never said… hngh… it couldn’t be my ass…”
Her tear-filled eyes were clearly melting with pleasure. The completely tamed bitch trembled as her plump rear quivered from even the slightest stimulation given by the boy she now recognized as her owner. Her lowered head was buried deep between her beloved older sister’s massive breasts.
Her whining, obscenely sweet cries sounded almost like adorable pouting.
The enormous penis slowly pushed into her tiny anal opening. It continued to twitch and pulse as he kept ejaculating.
“Khhhuu… It’s… too big… Khuuu… So… so biiig…!”
Even though he had trained her many times, Idrien still stiffened her entire body and broke out in cold sweat every time he first entered her. Marei reached out and affectionately ruffled her sweat- and semen-soaked hair.
“You love anal too, don’t you, Idrien? Ngh… Look how tightly you’re squeezing me while cum leaks out from below.”
“I-I don’t… hngh… love it… Wh-who says… I-I want it inside… first… every single day… deep in my womb… Aaaah!”
He mercilessly drove his cock into the young, fresh flesh. For a brief moment he felt something soft and squishy, then her rectal walls began to coil around him like a mad beast. The incredibly high body temperature and the seemingly bottomless depth of her tunnel brought him overwhelming pleasure. Marei continued his endless ejaculation, forcing his cock even deeper.
Squelch… Sluuurp… Sluuurp… Squelch…!
The thick semen he had pumped directly into her womb overflowed from her twitching slit, mixed with the load he had just shot into her ass. It poured down onto Ilien’s smooth lower belly as she struggled to support the weight of both her sister and their young master.
“Khhht… So tight… I love it, Idrien. You’re an excellent personal toilet. Excellent.”
“Ngh… Ngh… Uhhngh…..”
Since she had been the one to call herself that in front of the young boy, Idrien couldn’t even protest. Instead, the way he claimed ownership while pressing down and stroking her head made her unconsciously smile faintly. A surge of pleasure shot up her spine, making her hips tremble pitifully.
“Come on, relax a little more. Hngh… I’m still cumming. I want to shoot even deeper, Idrien. Good girl, good girl?”
From the moment he penetrated her ass, Idrien had become an obedient pet, completely submissive to the young boy’s every word. Of course, whether it was her front or back hole, once his cock was buried deep inside, she always turned docile.
“D-don’t… don’t pet my head like thaaat…. Ngh… If you go… deeper… Khh… I’ll… Uhhngh…!”
She raised her voice as if embarrassed by the affection from a boy much younger than her, yet in her doggy-style position she lifted her head to feel his touch more clearly, arching her neck back with surprising flexibility. The part of her body she once found repulsive had become the essence of pleasure, sending electric jolts through her brain. She drowned in the strangely delightful sensation.
“Khh… Khhuu… All the way in… Now I’m going to cum everything…!”
Sluuurp… Schluuuuurk…! Schluuuuurk… Squish… Squish… Squelch…!
With both twin sisters stacked on top of each other, the boy buried his cock to the hilt inside the younger sister’s rectum. His body shuddered as the dozens of seconds of ejaculation finally came to an end. He clung tightly to the exquisite female body beneath him, lying on her as he pumped the last drops of semen into her bowels.
Even after the long, drawn-out orgasm, his cock remained vigorously hard and scorching hot. It continued to throb powerfully inside the body he had just filled. Her rectum, now thoroughly lubricated with semen, provided the perfect slippery tunnel of flesh.
“Huu… Huu… You really do whatever you want… Saying you want to cum inside me but then flooding my ass instead. So… my… my ass-pussy… is what you like? Hmm? Hehe…”
Idrien tried to laugh triumphantly, but her voice was so small it was barely audible even to Marei, her face still buried in her sister’s breasts. She breathed deeply in satisfaction, feeling her sister’s body heat and the young master clinging to her back. Nothing could feel better than this.
“Huuu… Huu… Idrien, I’m going to start moving now.”
“Ah… Ngh… W-wait… Wait a seeeecond… Uhhngh… Khuu… Aaaang, Aaaah, M-Marei… If you move right now… Ahngh… Ngh… Haaaaak!”
Idrien had already climaxed easily just from being creampied in her ass. She wanted to savor the current calm a little longer, but the boy with boundless stamina who had stacked the twin sisters like a sandwich had no time to waste. Afternoon classes were far too short.
Squelch… Squelch… Squelch…!
“Hiiih… Hiiiit… D-don’t thrust however you want…!! Huuuaaaang…!”
Even though she sounded like she was crying out in pain, the ecstasy contained within her voice could never be hidden. Her sensual hips thrust back, the plump cheeks slapping loudly against the boy’s lower belly. The fleshy folds inside her hole squeezed him roughly, stroking him up and down as if milking him, then pulling him back in again and again.
“Idrien, you’re a toilet that loves getting fucked in the ass, right? Aren’t you? Say it quickly. Do you like your asshole?”
“Khuu… Khk…. Huuung… I like it… I like it…. Master’s cock is so full… so full inside my belly… Every single shape… hngh… when you press right there… Hngh…! Unyaaang, Hyaaat…!”
She had grown so used to it that the pain was now trivial. After being offered to her master dozens of times, the moment his cock began pistoning relentlessly in and out of her hole, Idrien burst into joyful sobs. She didn’t just squeeze him—she skillfully moved her inner walls like a living sleeve, wriggling and massaging him with expert devotion.
Squish. Squelch. Squelch. Squish. Sluuurp..
“Ugh… Good. It’s so warm and deep, I want to keep using it forever. Idrien’s ass-pussy. What a wonderful hole. I’ll reshape it to perfectly fit me. So squeeze me tighter! Tighter!!”
Marei began thrusting even harder into Idrien’s flower-patterned anus. He spread her elastic cheeks wide—the flesh so abundant it could swallow his hands—then drove his hips forward with all his strength.
Sluuurk…! Schluuuuurk….! Squish…!
Further. Deeper. Harder. Marei slammed his hips forward, roughly pounding Idrien who was buried against her sister’s body.
“Kahht….. Ahng… Ngh… Yes, Uuuwaaaaaah!! Ahh…. Ngh… Ahhng… Ngh… Uwaaang.. Uuuuump… Mmph…”
Watching Idrien scream wildly, Ilien quickly regained her senses. The sight of her beloved master and little sister passionately mating right on top of her made her shove her breast into her panting sister’s mouth.
“Make your sister feel good too.”
“Mmm… Chup… Sluuurp… Chup…”
Idrien thrashed in surprise at her sister’s sudden action, but once she understood the situation, she immediately began sucking hard on her twin’s breast. She chewed gently on the pink nipple with her teeth, melting their sticky sisterly bond into the sheets.
“Hehe, Master. I’ve been waiting too, you know? After Idrien, please use me thoroughly as well. Both my front and back holes are your personal toilets, available whenever you desire.”
Watching her younger sister cling so lewdly, Ilien gazed at her with mysterious eyes. She slowly stroked the head of the sister who looked exactly like her, then gave the young boy who was ravishing her a seductive smile.
The charm of an older woman. The relaxed, gentle demeanor Ilien showed—usually acting like a loyal puppy—made Marei unable to hold back. He roughly pulled his cock out from deep inside Idrien’s ass.
“Uuuump…! Hiiiiiiit..!”
Pfffrrrt…!
A cute sound leaked from her anus as he yanked out his tightly gripped cock. Idrien reached climax right in front of her beloved sister, her face completely twisted in pleasure.
Then, without pause, he shoved the massive meat rod—still glistening with a mixture of semen, intestinal fluids, and love juices—straight into the older twin’s vagina.
Sluuuuuurk…!
“Haaang… It’s… it’s iiiin…!”
“Ren. Your pussy… is squeezing me so tightly again… Hngh… I love it. No matter how many times I fuck you, it always feels like the first time… Uuugh…!”
The monstrously thick cock stretched her narrow entrance wide open. It slowly crawled through her twisting vaginal walls as if walking a path, pushing all the way up to her cervix.
“Haaang… Th-thank you… I-I practice… squeezing tightly every single day…! Aah, Ngh, Aaaang, Ahhng…!”
Come to think of it, she had mentioned going to yoga classes with Labella. She was training her flexibility to better clench her hips and thighs. Seeing the female so devoted to him that she even sought self-improvement, Marei grit his teeth against the fresh urge to cum that surged through him despite his recent orgasm, and began slamming his hips.
Squelch-squelch-squelch-squelch-squelch!!
“Aang… Haa… Haa… Khuu… Yes… Mmm…! A, Aaaaaang!!”
As he roughly stirred and pounded the sticky cave that was devouring his cock, Ilien clung tightly to her sister in her arms and let out wild moans. Inside her firmly gripping fleshpot, within the custom-trained sticky folds, her body had only barely adapted to her master’s shape. Every movement caused her to react violently, trying to adjust her inner walls to him, but the terrifying size of his massive club made that nearly impossible.
Having already climaxed many times, her hypersensitive body gently embraced his glans while her long tunnel squeezed his shaft with sticky devotion.
Schluuuck..! Squelch-squelch. Schluuuuuck!! Squelch-squelch-squelch!
“Khhhuu… Ah, Ahng. Ngh, Ah, Aang, Haaang… Aang, Ang. Ang… Haaaang..!”
Slowly at first, then more gently after the initial penetration, he loosened her tense body. Violating every common sense her body had memorized, Marei was brutally ravishing Ilien. He slipped his hand under her ass—pressed down by her sister—gripped her pelvis roughly, and slammed into her with full force.
The sight was nothing like her usual playful, puppy-like behavior. The moment she showed her mature, older-sister side, Marei could no longer restrain himself.
“Khhhuu… M-Master… Uwaaang… So… so rough… Hiiit… Gah… Gaaaaahhh…!!”
Ilien’s body shook violently. Her vaginal walls squeezed mercilessly, making long strokes difficult, but Marei didn’t care. He wanted to claim even this unfamiliar side of her. Not as the loyal dog Ilien, but as a woman. He wanted to completely devour her.
How? Simply by flooding her insides with his seed and making her his. He would impregnate her completely. Impregnate her.
Feeling the violent churning of his balls, which were endlessly producing semen waiting to be released, Marei thrust his lust even faster and harder into Ilien. He knew perfectly well that under Labella and Erden’s strict supervision he couldn’t impregnate anyone yet, but such thoughts had already been pushed to the back of his mind.
All he could think about was crushing the naughty bitch who had seduced him with this new side of herself and filling her with his seed. That was all that filled his brain.
From outside the window, the bell signaling the second afternoon class began to ring softly. The sun, hanging at its highest point in the sky, was slowly beginning to tilt. The hot, humid wind could not penetrate the tightly closed door.
Idrien Ksakru, who usually sat at her desk with a perpetually cold expression (a look she insisted was simply “strong-willed,” though others saw it as extremely sharp) writing academic papers, was not at her table at all. Instead, she lay sprawled across the bed she had urgently purchased just a few days ago, covering both eyes with her arm as she panted heavily.