Beside the Sisters
If you were to ask people to name the biggest difference between humans and animals, 99 out of 100 would say "reason." Appetite, sleep, sexual desire—unlike animals that live purely by instinct, humans live by suppressing their own discomfort and exercising cold, calculated control. Usually, this is explained away with the fancy term "socialization," but... that’s not what I’m interested in.
What I want to talk about is this.
"...Puhap, haa..."
People who want to enjoy things that aren't rational, aren't clean, and aren't socially respectable—things that are just, purely and simply, good—are often cursed at and called animals or bastards. But honestly? I think those people probably have a shameful bucket list hidden deep inside, too. If that weren't the case, then why would she do this?
"Ugh, chu-eup..."
"...Unnie, wait..."
Lee Hayoon, who was the closest thing to "normal" among us, was drunk on a twisted sense of superiority just from feeling her younger sister's jealousy a few times. Even though her own sister was trying to strip her boyfriend's pants and underwear right beside her, she didn't stop her. Instead, she stepped aside, closed her eyes tight, and tangled her tongue with mine. She was trying to get more attention than her sister, stroking my body and watching my reactions. It was Lee Jiyoon who had actually pulled down my underwear, but Hayoon was the one who gently stroked my glans before her sister could even touch it. Only then did she pull her hand away, as if giving her sister permission to touch me. And then... she wiped the pre-cum from her palm onto her own pajamas.
That’s impossible, right? She’s not some animal with her brain pickled in lust.
"...Look at how hard your cock is already. Ugh..."
On a bed too small for three people to roll around in, I sat, leaning back while holding the waist of Lee Hayoon, who had shoved her hand under my T-shirt to caress my stomach. As we kissed, I felt a pleasant warmth from below. Hoo— A deliberate sigh, clearly meant to gauge my reaction. Peh— A deliberate spitting sound, clearly meant for me or her sister to hear. While Hayoon was busy kissing me, Jiyoon—unheard by her sister—quietly licked the tip of my glans, which had been cleaned by her sister's palm, covering it in her own saliva like a cat. Then, using her saliva-slicked fingers, she stroked all the way down to the root. Because of Jiyoon, who was trying not to lose to her sister, and because of Hayoon, who was frantically tangling her tongue with mine to keep up...
"...Unnie, Unnie."
"...Pu-heu..., ...Why?"
"...Look at this. Seo Woojin's cock..."
"..."
"It used to be that my hand span wasn't quite enough..., ...but now it's not even close. ...Puh..."
Even with her sister staring right at her, Jiyoon used her own hand to measure her sister's boyfriend's length instead of a ruler. The cock that had only been slightly swollen a moment ago was now so engorged with blood that the shaft and root felt tight and stiff.
"Have you ever seen it like this, Unnie?"
"...I, I have...?"
"As expected.... So you're seeing it for the first time too, Unnie."
"..."
"...What else should I do for you? Is there something you want from me? ...Ah, should I rub it with my breasts?"
"...Don't talk to Woojin like that."
"Don't talk to him? Why? I'm just saying I know his tastes pretty well."
"...Don't. Just.... Just have sex and get out."
"Tsk.... Sigh..."
Jiyoon, who had been squeezing her breasts together, pulled a condom pack out of her pocket. She tore one open and neatly covered my hideously erect cock with the rubber sheath. Then, she rubbed the tip of the glans against her vaginal opening as if she were about to ride me, but then, as if a fun idea had just occurred to her...
"...Hey, Lee Jiyoon...!"
Instead of thrusting her hips down immediately, she collapsed forward, hugging me tightly and rubbing her face against mine. She didn't care that her sister's hand, which had been stealthily touching my stomach, was now wedged between our bodies. Perhaps, she was aiming for exactly that.
Even though she acted so relaxed, she was transmitting the sound of her heart, pounding loudly, into my body.
"Seo Woojin, can't you be the one to move?"
"..."
"Rather than me awkwardly shaking my hips.... ...It would feel better if you fucked me directly, like last night..."
Even with her sister listening right beside us. Whether she was talking about what happened on the living room sofa last night, or the dawn when we had sex while muffling our sounds so they wouldn't leak out... she said it in a way that made it confusing.
"...Then get into that position like you did then."
"...Okay."
Without Hayoon knowing. Just keeping a sulky expression on her face.
"..."
So that only I could understand, she deliberately grabbed Hayoon's pillow to bury her face in it, stuffed the blanket her sister had been using under her stomach, and got on all fours with her hips raised high. She was telling me to fuck her in front of her sister, in the same position she had used to cheat on her sister at dawn. Asking if this didn't turn me on, too.
"Noona. Wait a second..."
"...Ah, okay..."
...Crazy bitch. I only had the information that she liked games a lot. But once I peeled back the layers, she was a girl who had an inferiority complex toward her sister, who had a brighter personality than her. A girl who even practiced sex with her sister's boyfriend. A girl who was so insane that she allowed a 3P—and even helped enthusiastically—just for the reason that she wanted to show her sister that she was having sex with me.
I approached behind such a woman, pulled her black dolphin shorts down to her thighs with all my might, and grabbed her snow-white buttocks—which were already soaked with pre-cum even without any foreplay—firmly with one hand.
"..."
To the innocent sister of such a woman. ...No, to the sister who was no longer innocent, the sister who wanted me to acknowledge that she was better than her younger sister—I hugged her from behind. Quietly, so as not to be heard. While having her chest caressed by my fingers, while having her neck nibbled by the tongue that had been kissing me just moments ago.
"......Hi, euk..."
In front of her sister. Into the vagina that her younger sister was holding open with two fingers. ...I didn't just insert the glans; I shoved my cock in all the way to the root. So deeply that her buttock flesh was crushed.
"He-ek...? He.... ...Ung...?"
Usually, I would loosen her up a bit before thrusting, but maybe it was because I pressed straight down on her cervix without any of that today. Jiyoon, who had only been thinking about playing with her sister until a moment ago, shuddered, her raised hips and kneeling legs trembling as she tightened her vaginal walls. I imagined how good it would feel to drive her until she made only broken sounds, until she fainted—but that thought lasted only a moment. Hoo— With a wet sigh, I slowly pulled my cock out. If I kept going like that, I would end up filling this opportunity with nothing more than a tender time with Hayoon, just like any other day. To further stimulate Hayoon, who had started to go slightly off the rails somewhere along the line, I moved my hips slowly. Slowly, so she could remember the shape of my cock.
"..."
I had intended to hold back like that, but...
"...Hey, Woojin. Why aren't you doing it like you do with me...?"
Even though Hayoon, who had been kissing my neck softly just a moment ago, whispered that in my ear.
"Is it because Jiyoon looks tired, so you're going easy on her...?"
"...Yes."
"When you do it with me, you always fuck me violently, like you want me to die from climaxing..."
"..."
"Isn't that more your taste than being this gentle?"
"..."
"...You fucked me like that even when you ejaculated until you overflowed inside Jiyoon yesterday."
Every time I scraped her vaginal walls. Every time I lightly crushed her uterus. Even though I was whispering in a sinister, louder voice, as if to make Jiyoon—who was lightly climaxing with her face buried in the pillow—hear me.
"...When you do it with me, you don't have to hold back like this..."
"..."
"Let's do it right after you use up both condoms...?"
Even though Hayoon, who was hugging me from behind, stuck her hand between me and Jiyoon, who was dripping with pre-cum, and stroked my cock. Even though she licked my shoulders and neck, licking them as if to mark me with her scent while I was mating with Jiyoon. I had intended to hold back until you got used to it, Jiyoon. But you yourself...
"...Hey, Seo Woo, jin.... You said... I could... fuck me... like a beast... like last night... didn't you...♡"
Why are you pretending to be rational when we're the same kind of bastard? You crushed my patience, which was on the verge of breaking.
"...Ah."
I pressed Jiyoon's hips, which had floated up to make it easier to fuck, firmly downward. I pushed Hayoon, who was clinging to my back, away by her pelvis, telling her to move aside. Then, with my arms firmly planted on the bed...
"......! ...?! ......, ...♡ .........♡"
I began to thrust my hips violently, to the point where sweat was flying, just like last night when I had sex with Hayoon underneath me, just like that dawn when we had sex while muffling our moans so they wouldn't leak out, while breathing out heavy, excited gasps into the ear of Jiyoon, who had her head buried in the pillow.
"...Wow, wow..."
Was it because she had only felt it indirectly from below and had never seen it from the side? Or was it because, as Jiyoon said, she only looked for porn like this? Small exclamations leaked out between the sounds of flesh slapping against flesh. ...It would be normal to stop her boyfriend if he were having sex with her younger sister. But her reaction, just staring blankly and swallowing her saliva, made me feel like I was going crazy. Now, I lowered my posture even further, shoved my arm under Jiyoon's neck, and pulled her head in tight. Listening to Jiyoon's pleasant panting, which was whispered directly into my ear—'You fucking pervert...♡'—I slammed my lower abdomen against her buttocks, which kept lifting up to receive me deeper, even though she had called me a pervert. I hammered at her innermost part, the same erogenous zone as her sister's, over and over, as if to break it.
"Hey, yooo.... Even if you... fuck that... hard....... you can't reach... the uterus..."
Even in this situation, I bit the ear of the girl who was whispering playfully.
"...If we had done it... raw....... it would have felt... even better..."
Unlike her words, I looked down at her tongue, which was spitting saliva onto the tip of her tongue to make her sister's pillow permeable, gulping it down obediently.
"...Ah, ...hick, I'm, I'm cumming....... .........♡"
Until a moment ago, she had been forcing herself to act okay even if it was just talk, but when I rubbed strongly against her portio beyond the uterus, she climaxed immediately, her tongue twisting as if a switch had been flipped. I took her panting into my ears, filled my lungs with her scent—which I could feel even better because we were pressed so tightly together—and after thrusting my cock until I was on the verge of impregnating Jiyoon in front of Hayoon's eyes, I...
"...Chu..."
Byut, byu-eut.... Byu-reu-reuk.... For Hayoon, who had only approached after I had already started ejaculating... I planted my arms on the bed again. After mixing tongues sweetly, I...
"......Euk...?! ...Eut..."
"..."
...I threw the condom I had just pulled off—filled with enough semen that it might have burst—next to Jiyoon's head, so that Hayoon, who was watching with a blank expression, could see it clearly. The reason Hayoon had whispered such provocative things next to me. Furthermore, the reason she had shown such interest in foreplay. ...It was obvious that it was because of "that thing" Jiyoon had tipped her off about at dawn.
"..."
Whether I was truly turned on by the two of you playing lesbian. Whether, even if it wasn't quite lesbianism, doing it as a threesome had an effect. Whether that was why I had ejaculated so much. Whether, if I did something similar again, I could make her ejaculate as much as I did on the living room sofa.
"...Noona. Move to the side for a second..."
"..."
"...Noona?"
"..."
"Hayoon Noona."
"...Ah, ah...! Yes, to the, to the side...?"
"Yes. The condom pack from earlier... Hoo.... It was over there."
"...Aha......"
It was obvious that she had been stimulating me so hard because she was curious about things like that.