The Unprotected Promise
...Aha. Like me, Woojin had been holding back. He’d been suppressing himself, waiting until he couldn't take it anymore to finally speak up.
"...Can I put it in?"
"...."
"I asked if I could put it in."
"...."
Just like me, who couldn't bring myself to honestly admit my shameful preference for wanting him to be a little rougher. Just like Woojin, who had no other specific demands other than wanting to hear me call him Oppa and speak to me informally. He had been holding back, and holding back, until he finally let it out.
...Well, I suppose his acting as a delinquent threatening his underclassman to get laid was convincing enough. It was his first time, so he was a bit awkward, but he really gave it his all. As if he’d actually wanted to try raping a girl like that at least once... really.
"Just put it in. Your sister is probably in a safe... period, just like me."
"I didn't ask you."
"...."
Because of Woojin's cold reaction, Jiyoon, who had been clinging tightly to his side, cut her voice short. But that was all she cut short—just her voice. Her fingers, which had been touching my body, began to move much more explicitly than before.
Until just a moment ago, she had only been teasingly brushing her fingertips near my nipples, but now, she was flicking my nipples—which had become chillingly hard—with the tips of her slender fingers. Even though Woojin, who was already fully aroused, was looking down at us. As if to make him watch more. As if she were trying to make me so aroused that I couldn't control myself. As if she were, in a small way, taking her anger out on me.
Of course, the biggest problem was that I could have just grabbed Jiyoon's wrist and stopped her for a moment. But knowing what would happen, I remained a bystander... no, an accomplice, keeping my mouth tightly shut.
"...Can I put it in raw?"
"...."
"...Answer me. Hurry."
No. If we do that and I... get pregnant, what are you going to do? Are you going to take responsibility for everything? ...How ridiculous. You're barely a twenty-year-old boy. You were wearing a high school uniform just like Jiyoon last year, so what kind of responsibility are you talking about? So, doing it raw is... ...Ah, that, I, I don't mean let's have pregnancy sex all night long...! Enjoying that kind of deviation occasionally is something we should do after we've dated a little longer. At least until I graduate, we should date properly first.
...If I said, "At that time, I'll let you do all the condom-less sex you want...", that would have been the right thing to say. Rationally, that was the correct answer.
But with my cheeks burning red, the lips I had slightly parted to speak those words eventually closed again.
"Is it really a safe day?"
"...."
I quietly avoided his gaze, looking in a direction where I couldn't see Woojin or Jiyoon's face.
"Is it a dangerous day? Then?"
"...."
I was about to avoid their gazes as well, but then, slightly, almost imperceptibly, I shook my head.
And then, I blurted out something impulsive, something completely irrational.
"...Ah, just the tip... put it in..."
"...So you can pull out right when you want to ejaculate..."
"...."
"If you cum inside... ...Absolutely not..."
...It seemed Woojin felt much better doing it raw. And honestly... I was curious about what it felt like without a condom. Since it was a safe day, the chances of getting pregnant even if Woojin made a mistake in his excitement were extremely, extremely low. And if I wanted to lower those odds even further, I just had to make him promise to pull out.
...It's fine. Even if we do it raw. As long as we stick to that, it'll be fine.
"Hoo..."
"Ah, you absolutely cannot cum inside...? You promise...?"
"I'll cum on your lower abdomen. Is that enough?"
"...My lower abdomen...?"
"Or on Lee Jiyoon here next to us..."
"...."
"...You don't want that?"
"...Yeah."
As I gave a small nod, Seo Woojin's cock, which had been resting on my lower abdomen, brushed against my pre-cum-soaked clitoris and slid downward. He was going to use our transparent saliva as lubricant—along with my own arousal—to commit a dangerous act at the entrance of my stiff, dry hole, which had only been slightly loosened by his fingers earlier when he was with Jiyoon.
"Is this much okay?"
"...I... don't know..."
"I haven't even put the glans in all the way yet. Lee Hayoon, you usually take it all the way..."
"I know...! I know, but... wait a second..."
Press.
It was such a shallow insertion compared to usual, not even enough to tear my hymen. But that tiny pressure alone made my heart pound, clouding my mind. It was the sense of guilt that I was really doing it raw with Woojin. It was the guilt knowing that the same cock that had been buried deep inside Jiyoon, soaking up her juices, was now entering me raw. The guilt of knowing that the very thing Jiyoon and I had carefully licked clean was now inside me made my lower abdomen ache with a maddening sensation.
...Of course, I didn't know yet if doing it raw actually felt better.
"...I'll put the glans in all the way. It won't be long."
"Hey, Seo Woo...jin..."
"There's less than a finger's length left... ...It's okay, right?"
He pressed down hard on my thighs, scraping the front of my vaginal wall with his fully swollen glans as he pushed inward. I had imagined he might, but he didn't ignore our promise to only put the tip in and start thrusting away. He really only shoved it in up to the glans, scraping against my stretched vaginal walls and sending shivers of pleasure through me.
...Usually, he would have stroked my hair and waited until I said I was okay. If I had tried to push him away with my hands like this, he would have pulled out immediately and asked if I was alright. But those words he spat out, casting aside all kindness and driven by pure desire—the raw sexual urge to ravish me regardless of my state—and that... sensation of us rubbing together raw... was, surprisingly, quite good.
"Hoo..., ...damn... you're so wet, but it's so tight it's driving me crazy..."
"Hi..., ugh.... Ah, don't rub the top..."
"...You look like you're enjoying it, sister."
"Eek...?!"
Even though we weren't in the middle of that embarrassing roleplay where a naive underclassman threatens his senior until she becomes addicted to masturbation, Seo Woojin spat out light profanities while grinding against my vaginal walls. Because of that, the throbbing pleasure in my lower abdomen, the sensation in my nipples—which he was teasing in a way that felt like how Jiyoon masturbated—and the pleasure of Jiyoon, who was clinging to my side and licking my ear like a cat, all felt surprisingly good and not at all repulsive.
Even though he had only been persistently stimulating the entrance of my vaginal wall, my shameful moans began to spill out one by one.
"Haa.... Ugh, eek......."
But these moans were a little different from the ones I usually let out. They were a bit more demure. A bit quieter. A bit shorter.
...It was obvious, of course. Usually, his cock would be pounding against my cervix, but now it was only scratching the entrance. It was a place I had touched many times with my own fingers. ...It was impossible to be satisfied with just that.
"Ugh, ooh......."
It was a pity. I let out a damp sigh, chewing over the inner thoughts that had blossomed in my mind and remained like the lewd patterns in an erotic comic. If he had scratched the front like this with a condom-covered cock, would it have felt this good? If he had shoved it all the way in and pressed against my cervix, how good would that have felt? Would I have been able to finish just by throwing my head back and panting out breathless gasps like usual?
...Would I have fainted from the sheer amount of arousal right in front of my younger sister?
"...Haa...ugh....... Ooh......."
But with his cock only two knuckles deep like it was now... I couldn't get that kind of stimulation. I could only tremble my shoulders with the agonizing, unfulfilled pleasure.
"...."
Just as I had soaked the area beneath my hips with the silent, leaking arousal, Woojin, who had been looking down at my stomach and letting out a long sigh, simply...
"──Eek?!♡"
Without even asking me. On his own whim. He shoved it all the way in, grabbed my trembling thighs, and... thwack, thwack. Twice. Three times. Four... times. Five.... .... Seven, eight, .... ...Ten times....
He shoved his fully swollen, raw cock all the way to the end of my vaginal wall, stimulated my vaginal opening to his heart's content, and then pulled it out. It was a pleasure far more vicious than I had imagined. A pleasure so vicious it completely scrambled my brain.
"....... ....... .........♡"
"...Whoa."
He sprayed another layer of that transparent liquid, which made me feel like dying of embarrassment, onto his cock, which was already soaked in arousal and standing stiff. Splurt, splurt. ...And then another layer. Drip.
"Hi, ugh...."
That was all. A moment ago, he had done such a thing without a word to me, but now he had gone back to scratching my vaginal walls with just the tip, as we had promised. ...He could have at least made a lame excuse about it being a mistake. Or honestly told me he was just horny. Either choice would have been fine. ...Why, why wasn't he saying anything?
"Hey, ugh.... Why did you... put it all the way in just now...?"
"...I never did that. You idiot."
"What kind of bull..."
Just before I could spit out the word "bullshit," Seo Woojin pressed down on my thighs again, hard enough to make the veins in his forearms pop, and inserted himself. My heart pounded in my ears, and I clutched my pillow, but... strangely, he didn't thrust away until my brain felt like it was breaking like before. He just shoved it in about halfway, looked down at me—who was clenching my pussy without a word—and then pulled it back out without thrusting any further.
"...."
Hoo, hoo. As I finally began to exhale the breath I had been holding, I heard Jiyoon giggling right next to me. ...I suppose she hadn't heard my heart pounding because it was too loud.
"...You did."
"...."
"Hayoon?"
"...Eh?"
"You told me to only put the tip in when you first gave me permission."
"...I did..."
"So I'm keeping my promise.... ...What's so strange about that?"
It was strange. That promise, even just now, even a few seconds ago. He hadn't kept it.
"...Hey, Lee Jiyoon. You saw it from the side too.... Woojin went all the way..."
"I didn't see it. Me?"
"...What? You didn't see...?"
"I've been licking your ear this whole time, sister. Of course I didn't see it."
"...."
That's impossible. Even if you didn't see it, you must have heard the... thwack, thwack, the loud sound of him thrusting away. If it were true that he only put the tip in as promised, how could you hear a sound like that? Doesn't that seem strange to you, too? Did I have a dream for a moment? But seeing Woojin's lower abdomen soaked, I was clearly...
"...Ugh......."
...Thinking such things, I groaned in agonizing pleasure as he pressed down on me a few more times in earnest, leaving me unable to be satisfied with just the tip tickling me.
"Lee Hayoon."
"Hi, ugh...?"
Woojin spoke, pushing his cock in a little deeper. ...Really, really a little deeper.
"...Are you satisfied? With just this much?"
"...."
If I hadn't known the pleasure of being pounded raw all the way in, I might not have known. But because he had ignored my words and pushed me as he pleased just a moment ago... my simple, simple instincts were forced to completely override my reason.
"...You just have to pull out before you cum, right?"
"...."
"I'll pull out the moment I feel like I'm going to ejaculate. ...Okay?"
"...."
Ten seconds passed without me giving permission or refusing. Even though Woojin was leaning down and demanding a kiss while keeping his cock pushed in just like before... instead of barking at him to pull out quickly because it was dangerous, I was being a fool. In front of my younger sister, I was forced to look up at him with my tongue caught on my lower lip, saying words that made me feel pathetic.
"..., .........♡"
Even though I had thought that doing it raw was absolutely forbidden. Even though I had said that if he were to put it in, he should only put the glans in slightly. As his fully swollen glans began to noisily crush the back of my womb, which had been starving for pleasure, those rational demands began to disappear from my mind, one by one.