Chapter 161: Side Story - Bunker (19)
Chapter 161: Side Story - Bunker (19)
[Archived Instructions]
[Goal: No sex between resident Kang Yu-min and resident Kang Yu-jin for (7) days]
[Reward: Creation of a comfortable living room including a TV connected to OTT services, the latest gaming console, a PC, a library of curated books, a sofa, and a spa]
[Progress: 6/7]
Five days.
Five more days had passed since that first day, and now, my sister and I were naked in the bedroom.
There was no need to waste breath explaining what had happened during those five days.
We were unintentionally worked up, feeling as if our ejaculations were being strictly managed.
We lived with the thought that we could have sex in a week, making it clear how much we were looking forward to it.
Furthermore, we acted as if we didn't even care about the reward anymore.
We had even reached the point of walking around naked.
In fact, it felt more natural to be naked than to wear clothes now.
Ever since the progress reached 4, we hadn't even masturbated. I held back so that I could have a pleasurable ejaculation—one that would last until I was satisfied—and Kang Yu-min, seeing me like that, didn't masturbate either. She spent her days with a dazed expression, her skin flushed with arousal.
It was the same right now.
With my erect cock pressed firmly against Kang Yu-min’s lower abdomen, I overlapped my lips with hers, panting as I swallowed my saliva.
Our tongues tangled together, and a steady stream of sticky pre-cum coated her from her lower belly down to her pussy.
The excitement, which felt almost painful, seemed to intensify as time passed. Knowing that only sex was forbidden, we acted as if possessed, kissing until our lips were swollen and sore all day long.
As the time ticked down, we intended to keep going until we crossed midnight and completed the directive.
Feeling Kang Yu-min’s arms wrapped around my neck and her surprisingly large breasts crushed against my chest, I trembled slightly and pulled my lips away for a moment.
As if she couldn't stand even that brief separation, Kang Yu-min bit her lip and clung to me peevishly. I pulled her close, rubbing my cock against her firm yet soft skin, overcome with arousal.
“…I think I’m going to cum.”
“Hold it in. You pervert.”
“You’re the one dripping pussy juice everywhere right now.”
“No, I’m not. That’s fluid from your dick.”
“Stop being so coy.”
“Why? Am I not cute?”
Kang Yu-min turned her face slightly toward me, and our eyes met. It was too embarrassing to answer, so I pressed my lips to hers again. She stroked my cheek and responded to the kiss.
Maybe she was doing this on purpose. Maybe she knew that if she acted like this, I would keep kissing her.
But what did it matter? I continued to kiss her, feeling her pussy pressed tight against the base of my cock. I felt her pussy juice soaking my testicles as her folds seemed to twitch and lick at them, and I looked forward to the result we would reach in just a short while.
“Phew…”
Kang Yu-min pulled her lips away, letting out a heavy, cute breath. A long string of saliva wove between us, wetting our necks and mouths, but neither of us thought to wipe it away.
Honestly, it felt like a waste to do so. I stared into her eyes, thinking about how I wanted to shove it in and cum right this second.
“I want to try it from behind.”
“From behind…?”
“Yeah. I want to grab your ass and pump you from behind.”
“…Haaah.”
A hot breath escaped her lips. With trembling legs, Kang Yu-min moved away from me, leaned over the bed, and turned around.
Her large, fuckable ass was revealed.
It was an ass that made me want to bite it and leave teeth marks, and it still had a faint Mongolian spot on it.
“You still have this.”
“What?”
“The spot.”
“Ah… yeah, I guess so.”
Since I couldn't see her face, I felt a strange sense of regret for some reason, but I also felt relieved she couldn't see me as I rested my cock on her buttocks.
The heat, the pulsing. Everything was enough to drive her crazy. Whether she realized it or not, Kang Yu-min let out feverish sighs and moans, naturally lifting her hips and lowering her upper body into a perfect position for penetration.
“You took the pill, right?”
“Huh? Y-yeah…”
“Then… once it’s past midnight, we’re having bareback sex, okay?”
“Yes, I’d like that…”
“I’m going to fill you up inside.”
“Yes, please… please…”
The excitement revealed by her heated breaths felt contagious. Even I was thinking about just shoving it in right now.
But I had to endure. It was better not to do something I’d regret later.
Instead, I thought back to the new directives we had received over the past five days.
Most were for food, drinks, and clothes.
But only one of them was truly important.
Kiss for 6 hours. Reward: Birth control pills.
It wasn't even hard to achieve. Strangely enough, we cleared that directive easily.
Was it because after waking up and checking the terminal, we spent the whole time lying in bed kissing?
We decided to use the result of that effort now.
Since it was our first incestuous sex in a week, we figured it was only right to go for a creampie.
In that sense, I could understand the words Kang Yu-min suddenly spoke.
“Hey.”
“Yeah.”
“We’re going to have sex in a little bit, right?”
“…Yeah.”
Her faint breath was a mix of arousal, a sense of depravity, and perhaps an anxiety that this might be wrong.
“Are you really… going to have sex with me?”
“Yeah, I am.”
“Will it be okay? I’m… your sister. Your real sister.”
Even though she knew this was what the directives wanted, it was a question she had to ask. It wasn't exactly the kind of conversation to have while my cock was resting on my biological sister’s ass, though.
I spoke while trying to steady my ragged breathing.
“We’ve already done it.”
A chill ran through the air. As I brought up the truth we had tried to brush off as just 'masturbating each other,' both Kang Yu-min and I shuddered simultaneously.
Yes, we had already had sex.
Sticky, incestuous sex, using clumsy excuses and justifications as a shield.
Purely for each other's pleasure.
But her question felt like it was signaling the end of those excuses. Looking at her twitching pussy, I reflexively hooked my hands onto her hips.
“Hic!” The sound of her catching her breath was sweet.
“You already took your brother’s cock all the way to your uterus. Your cervix got pounded, and you climaxed while getting a creampie in a condom.”
“That’s not… it…”
“If that’s not it, then what is it?”
Kang Yu-min hugged a pillow. It was my pillow. A pillow soaked in my scent.
Just watching that sight made my brain feel like it was short-circuiting. I had a premonition that the biological sister in front of me would start to look like something else entirely.
A scene that made me think she might look lovely or cute beyond just being a sister.
Looking at her, I unintentionally sucked in a breath.
“What are we to each other?”
It felt like the moment of truth had arrived. I struggled to find the words and remained silent for a moment.
“I don't think we're just siblings anymore.”
She was right. Normal siblings don't have sex, and even if they did, they wouldn't prepare for a messy creampie session after a week of abstinence.
I wondered if we really needed to have this talk right before insertion…
But I felt this was something that definitely needed to be addressed.
If not, we wouldn't be able to maintain this relationship for long.
So, I swallowed hard and asked first.
“What do you want us to be?”
Kang Yu-min fell silent at my question. Was it because it wasn't something that could be answered easily?
However, I had a vague idea of which direction this needed to go.
“The world ended.”
Her voice came out gloomy. I affirmed her with silence, and she took a moment to pick her words.
“I don't know how much is left out there, but it seems certain that almost nothing of the world remains.”
“Right.”
“And, maybe… we’re the last man and woman on Earth.”
It was a thought I’d had a few times myself. To be precise, it was something I thought about before we started having sex.
I had been disgusted by the idea, thinking I’d rather die than have it turn out that way, but now that the situation was upon us, it wasn't that disgusting.
“And?”
“I mean, that…”
Even then, Kang Yu-min couldn't bring herself to say the most important part. As time passed, I saw the clock on the terminal I’d turned on earlier ticking away.
“Are you saying we might have to rebuild humanity?”
Without a word, Kang Yu-min hugged the pillow tighter. I slowly moved my cock, which was resting on her ass, and rubbed it against her butt crack.
Kang Yu-min let out a moan at the sensation of the sensitive skin being stroked, and in response to that moan, I let pre-cum drip onto her back.
“Are you saying you might have to get pregnant with my cum and give birth to my baby?”
“…Yes.”
“Do you want to?”
“I don't know.”
To be fair, it wasn't a light topic. Pregnancy—and incestuous pregnancy at that.
But she was saying she could do it if it was necessary. However, I didn't think what lay behind her words was a sense of duty.
So, I let out a sigh.
To put into words what Kang Yu-min couldn't bring herself to say.
“You’re trying to say that since we’re Adam and Eve, we have to become a married couple even though we’re siblings, right?”
Having her true thoughts pierced, Kang Yu-min’s hips twitched as she asked.
“You… hate it, right?”
In her trembling voice, I could hear the fear and worry of being rejected, and the anxiety about what would happen to our relationship after this.
I couldn't bring myself to say I hated it or that it was disgusting.
There were already feelings born from our sexual chemistry, so I couldn't say that.
“Shall we start by dating?”
Silence fell after my answer.
Kang Yu-min kept her hips raised but buried her face in the pillow, her ears turning bright red.
“What are you saying…”
The answer she finally squeezed out was coy and cute. My cock throbbed, and sensing it, Kang Yu-min quietly buried her face deeper into the pillow.
Soon, a muffled voice could be heard.
“Getting worked up over your own sister and even confessing. You pervert.”
I quietly shrugged my shoulders, and Kang Yu-min added as she gently swayed her hips from side to side.
“It’s my fault for having a brother like you. A-anyway… I’m the only sister who would put up with a pervert brother like you… so I’m only accepting because I have no choice.”
While coating my cock with her pussy juice, she was acting charming with her pussy.
I listened patiently to her pathetic excuses until the clock on the terminal finally hit 00:00.
“You should be gratef—”
I grabbed her cheeks and pulled her ass open, shoving my bare cock inside her without a condom.
With the sound of sticky fluids and vaginal walls parting, her starved pussy accepted my cock deeply. Finding the slightly protruding cervix within the vaginal walls, I kissed it with the head of my dick.
“I’m cumming in your womb.”
“Ah, ugh, haah…?!”
I ejaculated just like that.
“Ah, inside… you’re cumming inside…”
As I filled Kang Yu-min’s uterus with my semen, I had the exact same thought she did.
‘Yeah, I’m the only brother who would put up with a pervert sister like this, so I guess I’ll have to be her husband.’
In the end, I guess siblings really are siblings.