The Sister's Calculated Silence
Same day, 10 a.m.
I quietly opened the lecture hall door. The lecture had already begun.
The professor’s voice echoed through the entire room via the microphone, and the spacious hall with two hundred seats was nearly full.
Rows of backs dyed in every color stretched along the tiered seating—brown, black, blonde, even blue hair visible here and there.
Rubbing my wrist, which still throbbed with a faint ache, I searched for my empty seat.
Third seat from the window in the middle row on the right. That was my assigned spot.
Unlike other universities, Seohan University enforced an assigned seating system. It was an official rule written into the school regulations: whichever seat you chose during the first class of the semester became your permanent seat for the entire term. If you wrote your student number and name on the seating chart that first day, the professor or teaching assistant would use it to take attendance. The system was strict enough that sitting anywhere else or having no name on the chart could result in an absence, so even if you were late, you had no choice but to go to your own seat.
I slipped quietly into my chair.
The professor was pounding the blackboard with his fist, passionately explaining something, but even though he saw me come in, he said nothing and simply continued the lecture.
The guy next to me glanced over with a look that clearly said “Why are you so late?” but I ignored him and pulled my laptop out of my bag.
It was a four-hour block, so after listening from nine to eleven, we were given a twenty-minute break.
While the other students headed to the restroom or crowded around the vending machines, I quickly made my way to the front and stood before the professor.
He took a sip from his plastic bottle and looked at me with a blank expression.
Just as I was about to open my mouth to apologize, he spoke first.
“Why were you late?”
He had stolen the initiative.
The apology I had prepared in my head scattered.
“Well… I overslept. I’m sorry.”
I couldn’t bring myself to say that my little sister had tormented me all morning.
The fact that I had been stripped naked while half-asleep, tied up, forced to climax twice with an onahole, and then locked into a chastity cage was something I would never speak aloud, not even on my deathbed.
“Well, no need to apologize.”
The professor closed the bottle cap and spoke calmly.
“Being late only hurts you since you miss class. But you know that too many tardies will affect your grade, right?”
“Yes… I know.”
At this point, my attendance score for the semester was already a little lower, so there was no point in making excuses.
“What happened to your wrist?”
His gaze stopped on my wrist.
The faint red marks left from being tightly bound to the bed frame by my sister were still visible on the skin I had been unconsciously rubbing.
“Haha, I twisted it while playing a game…”
I laughed awkwardly to cover it up.
There was no way I could say, “My sister tied me up and used an onahole on me.”
“I see. Be careful.”
“Yes, sir.”
The professor nodded and began organizing his lecture materials again. I quietly stepped back and returned to my seat.
The lecture ended at 12:30. My stomach growled.
Skipping breakfast and sitting through four straight hours of class had left me completely drained.
I needed to eat lunch, but my feet naturally carried me toward the convenience store instead of the student cafeteria.
I grabbed a tuna mayo lunchbox, a triangle kimbap, and a coffee, paid, and headed for the club room.
I didn’t have any friends to eat with, and I hated the idea of other people seeing me eating alone in the cafeteria. These days plenty of students ate alone, so maybe no one would care, but I still minded.
Sitting by myself in the middle of a cafeteria packed with hundreds of people made me feel self-conscious, as if everyone was thinking, “That guy has no friends.”
Of course, it was probably just my own paranoia, but the discomfort was real.
The club room was quiet and empty—perfect for eating alone.
After finishing my meal and attending my afternoon classes, I returned to the club room once more.
I sat in the old chair, opened my laptop, and pretended to work on assignments while waiting for Eunbi.
Four o’clock came. Five. Six. But for some reason, Eunbi never showed up today.
I felt a twinge of worry. There had been no contact since we left the hospital together yesterday. Maybe something had happened.
Or had I done something wrong?
I shook my head. There was no need to panic over her missing just one day.
She was beautiful enough to be called the school’s number-one beauty, a twenty-year-old freshman. Of course she had tons of friends, and plenty of guys would be clinging to her because she was so pretty and young.
Back in the first semester, her social media had been full of photos with friends—group shots from parties, selfies at cafés, scenic pictures from trips.
Before joining this club, she had clearly been enjoying a vibrant university life. It was only natural she wouldn’t come here.
If anything, the strange thing was me showing up every day in this dreary club room.
Feeling a strange mix of relief and disappointment, I left the club room.
The relief came from the fact that the devilish girl hadn’t appeared, so I could relax. The disappointment… why did I feel disappointed? I wasn’t sure.
It was probably just because I had gotten used to it.
The walk home felt heavy. These days, home scared me more than the club room.
From now on, I would have to keep acting in front of my sister like the kind of older brother who enjoyed cross-dressing.
That morning I had claimed the women’s clothes hidden in the closet were because I “liked cross-dressing,” but Jiheon didn’t seem to have completely bought it.
I had no idea when she might interrogate me again.
When I arrived, the house was empty as expected—Jiheon was still at her cram school. The living room lights were off, and her door was firmly shut.
Letting out a sigh of relief, I went into my room.
I flopped onto the bed and stared at the ceiling with another sigh.
Normally I would have jerked off, but thanks to the chastity cage my sister had forced on me, that was impossible now.
Ugh… this is torture…
Doing it more than three times a day had been normal, and now that I was forcibly prevented, the frustration was overwhelming.
Not only masturbation—now I had to practice complete abstinence.
The moment I saw anything even slightly erotic, my cock tried to get hard inside the cage, creating intense pressure.
To suppress this raging libido, I had no choice but to live like a monk.
Left with no other option, I lay face-down on the bed and turned on a streaming site.
Game videos, mukbang, vlogs…
But whenever an erotic thumbnail or suggestive content appeared, I quickly turned the screen off and clutched the chastity cage in pain.
Even when I got hard, the extremely small and flat cage hurt so much that the erection quickly subsided.
Getting hard meant pain. It hadn’t even been a full day since the cage went on, and I was already suffering.
If this sexual frustration kept building, it would only get harder and more painful to endure. How was I supposed to hold out…?
I couldn’t even last a single day, let alone a week. Should I just kneel and beg Jiheon to take it off…?
But my pride wouldn’t allow it.
Still, I could already picture myself, after more than a week in this state, completely naked and bowing my head to my sister, begging her to remove it.
Too scared that an erotic ad might suddenly pop up, I became afraid to even touch my phone.
Yeah, let’s turn the phone off and meditate. There must be a reason monks meditate…
I closed my eyes and tried to stay as calm as possible. Yet only one thought filled my mind.
I want to jerk off so badly…
Soon memories flooded in: being cross-dressed and tied up in the women’s restroom by Eunbi, getting my ass violated; riding on top of Eunbi in a nurse uniform, moving my hips on my own; the deep kiss with Eunyoung inside the narrow cabinet; climaxing just from my sister touching my nipples; being forced to climax with an onahole by my sister.
A pressure far stronger than usual built up in my lower body.
“Nngh… someone save me…”
The erection inside the cage refused to die down.
I’m never meditating again…
Two days passed after that, but my sister never snuck into my room, nor did she mention the chastity cage or the cross-dressing.
She was clearly tormenting me slowly under the guise of indifference, watching me squirm from the cage.
Thanks to her, I was in absolute hell. As much as I hated to admit it, my sister’s “tease the big brother” strategy was working terrifyingly well on me.
We were locked in a tense battle of wills over who would approach first, but if things continued like this, I was obviously going to lose.
This was a fight I could never win against a sister who knew me better than I knew myself.
Strangely enough, Jiheon understood her own older brother—me—far more thoroughly than I did.
What I usually watched, what I wanted, what I liked, what I hated, my sexual preferences, how many wrinkles my balls had, the exact length of my cock in centimeters, which parts of my body were sensitive, how to make my cock and nipples stand up instantly—she had somehow figured out every piece of information and every weakness I didn’t even know about myself.
If I stayed quietly in the palm of her hand, this perverted sexual desire would keep rising like an exponential graph, growing steeper and steeper.
The day when this explosive, lewd feeling became unbearable would come soon.
Now that three days had passed with the chastity cage on, my desire to climax had already crossed the critical point of that exponential curve—the moment when a gentle increase suddenly becomes a steep one. With no way to control the rate of increase, all I could do was suck on my fingers and tremble while waiting for the slope to turn nearly vertical.
And Eunbi still hadn’t come to the club room.