Chapter 38: The Devilish Twin Sister Strikes [R-18]

My heart pounded loudly in my chest, as if it were right next to my ear. Yui paused her phone game, sat up, and stretched her arms and back before fixing her gaze on me.

"Did you have fun with Chinatsu-san on your date?"

"Huh? N-No, Yui, we didn't go on a date. We're not even in that kind of relationship," I stammered.

Yui's grin widened.

"Not only have you lost your virginity, but you've also become quite the liar, onii-chan. Too bad I already know that the three of you are in some unique arrangement."

How did she find out? I was tempted to ask, but knowing Yui, I decided not to press the issue. I knew her all too well. She'd go to great lengths to find any weaknesses and often did it in her own extreme way. Normally, it involved pranks, but this time, it felt like something more serious.

Yui finally got off the bed.

"Close the door, onii-chan. If we don't, who knows what the folks in this house might overhear."

I hesitated for a moment, my mind racing with uncertainty about where this conversation was headed. But knowing Yui's unpredictable nature, I closed the bedroom door as she had suggested, trying to keep our discussion as private as possible.

As I turned back to face her, Yui had a sly look on her face. "You know, onii-chan," she began, "I've been thinking about this unique relationship of yours with Chinatsu-san and Natsumi-san. It's pretty bold, isn't it?"

"I-I already told you, we're not in any kind of relationship. We're just friends, that's it. Besides, the idea of the three of us in a polygamous relationship? That's not something that's accepted in Japan," I stammered.

She chuckled, her eyes glinting with mischief. "Oh, come on, onii-chan. I'm not a kid anymore. I can see there's more to it than just friendship. And I'm not here to judge. In fact, I might have some interesting ideas to make things even more exciting."

"Yui, don't even think about it. We're happy with the way things are."

She shrugged nonchalantly. "Just offering some fun suggestions, that's all. But speaking of fun, I've got something else in mind right now." Yui's gaze locked onto me with an intensity that sent shivers down my spine.

"What do you mean?"

Her grin widened, and she took a step closer. "Well, onii-chan, it's been a while since we had some sibling bonding time, don't you think?"

I caught a faint whiff of soap from her, making me wonder if she'd showered before I got home. Strangely, that hint of soap was working its way into my mind like an aphrodisiac, clouding my judgment. I knew this was wrong, but I couldn't help but be drawn into whatever twisted sibling bonding time she had in mind.

She leaned in closer to me. Despite being twins, I was taller than Yui, probably because I was male and she was female. Her scent was now overpowering, and my nostrils seemed to widen, greedily taking it all in.

"Let's have some fun bonding time, onii-chan," she purred. "And I promise... this bonding time will feel even better than your escapades with those two."

Yui's hand ventured from my chest down to my crotch, and I gasped. "Yui, where are you touching?" I protested weakly, though I didn't stop her. My willpower was slipping.

"You're already so hard, Onii-chan," she teased. "Are you perhaps expecting something?"

I struggled to find the right words, torn between confusion and desire. Yui's touch was electrifying, and I could feel myself growing even more aroused beneath her fingertips.

"Yui, this... we can't," I stammered, my voice barely more than a whisper.

She didn't seem deterred by my feeble protest. Instead, she leaned in closer, her lips dangerously close to mine. Her hot breath danced across my skin as she whispered, "Onii-chan, why resist something that feels so good?"

She began to unbuckle my pants, and that was my breaking point. This was going too far, and it was dangerous. I firmly grabbed her hand.

"Stop this, Yui. We can't do this," I urged.

"Your head might say one thing, but your other head is saying otherwise," Yui whispered, her words like a tempting spell. "You know, sometimes, you have to use not only your head up here," she tapped my temple, "but your head down there, onii-chan."

Her words were like a tempting spell, messing with my thoughts. This was pushing the boundaries, heading into that twincest territory Kaneda mentioned. I swallowed hard as I reluctantly released my hold on her. My desire was getting stronger, and since I hadn't done anything to erase the memories of the previous night, this lust felt like it wouldn't fade unless I ventured down that forbidden path.

"Hehehe... It seems you've finally realized that resistance is futile," Yui chuckled. "And even if you try to resist me, I've already sunk my teeth into you. You're trapped now, unable to escape the poison corrupting your body. In other words, you can't run from me any longer."

I stood there, feeling powerless, as she skillfully unbuckled my belt. The zipper let out a distinct sound, and she gracefully went down on her knees. My pants and boxers were tugged down, freeing my erect penis. It sprung to life, and she leaned in, sniffing it eagerly, her breath heavy like a dog in heat.

"Haa... Haaa... I adore the scent of your arousal," she purred, her panting adding to the intense atmosphere. She drew nearer and planted a kiss on it, sending an electrifying shiver down my spine. "Seems like you had an encounter with Chinatsu-san, judging by the scent of semen on your dick. Allow me to cleanse you, so that woman's aroma is no longer clinging to you."

She proceeded to lick my shaft. My own twin sister was performing this act.

"Th-This is a terrible idea, Yui. It's just not right," I protested.

"There's nothing wrong with it, onii-chan. I love you, and girls who are as infatuated as I am would do anything for their beloved," she insisted.

"B-But we're siblings... doesn't that make it strange?" I stammered.

"It's not strange at all. We're special," she replied with conviction.

Special? What did she mean?

"Special?"

"Aren't we? Unlike typical siblings, we've been apart for a really long time."

I couldn't quite grasp how that made us "special." To me, it felt unprecedented but also perfectly natural. Twins whose parents had separated were no different from any other siblings with divorced parents. The father took one child, and the mother took the other. We were essentially like any regular pair of siblings out there.

However, I didn't voice these thoughts. Without me even realizing it, Yui had already taken my penis into her mouth.

"Wow..."

The sensation was mind-blowing, unlike anything I'd ever experienced. I had no idea where Yui had learned to do something like this. She pulled back, a trail of her saliva connecting from the head of my dick to her lips.

"How was that, onii-chan?" she asked with a seductive smile. "It feels good, doesn't it? Nothing like anything you've experienced before. After all, those two probably don't know anything like this, considering they aren't as experienced as I am."

"Where did you learn how to do that, Yui?" I asked, my curiosity overriding the situation.

"I've been practicing every night," she admitted with a seductive grin. "Using your dick." Oh, right. She mentioned that she had been drinking my semen every night, like some sort of succubus.

She flashed that seductive smile again, before guiding my dick deeper into her mouth and down her throat. Unlike other orifices, a mouth-pussy had a unique tightness, and the way her throat constricted provided sensations unlike anything else.

"Ugh, Yui, please stop," I pleaded.

"You're still saying that?" She chuckled. "But, onii-chan, your dick seems quite happy, see?"

"Urk."

I never imagined I'd find myself in this situation with Yui. It was unbelievable that my usually well-mannered twin sister was now performing such explicit acts on her older twin brother, her face twisted with perverse desire. Her eyes, as she looked up at me, held a debauched gleam.

"Fu... Does my blowjob feel good?" Yui purred, her voice dripping with seduction.

O-Of course it did. The more I dwelled on the taboo nature of our actions, the stronger the waves of illicit pleasure washed over me, making it feel even more incredible.

"Ah, you're sucking so hard!"

I could feel myself reaching the point of no return, so I attempted to pull her mouth away from my throbbing arousal. Instead of releasing me, she tightened her grip, her arms encircling my waist.

"Wait, Yui! I'm..."

"Do it, onii-chan. Cum! Cum inside my mouth!"

I couldn't hold back any longer. With a final shudder, I erupted, spilling my milky fluid into her throat.

I had actually gone through with it... Guilt gnawed at me, but there was no denying that cumming inside my twin sister's mouth had felt absolutely incredible. It was like my very soul had been drawn into the sensation.

"H-Hey, Yui, you're sucking so hard... I've already cum," I gasped.

Yui finally pulled back, a sly smile on her face. "Well, if it dripped down, it could've caused us some trouble down the line. It's better if I swallow it now, right?" She opened her mouth, showing me its empty interior. She had already swallowed every drop. "Onii-chan, thanks for the meal."