Damn it. I'm screwed.
My mind went blank.
Could there be a situation worse than this?
Subin, who had been on the verge of confessing to me in that tender atmosphere only moments ago.
I'd been caught receiving a blowjob from my younger twin sister in Subin's living room.
It felt as though my heart had plummeted all the way to the floor.
I was sure Subin would either get incredibly angry or glare at me with contempt and yell at me to get out immediately.
Actually, crying seemed even more likely.
She had just been horribly betrayed in her own home by the man who had just thanked her for becoming his friend.
But then.

“Ah….”
Contrary to my expectations, however, Subin's reaction was surprisingly calm.
She was certainly surprised, but she didn't look horrified or shocked as I'd imagined.
She widened her eyes for a moment, then gave a faint smile as though she'd grasped the situation.
“You were getting sexual relief?”
Subin spoke so casually and sat down naturally at the table.
“…Huh?”
This time, it was my turn to panic.
“Oh, if my being here while you're getting sexual relief is making you uncomfortable, should I step out for a while?”
Subin was the one worrying about my feelings instead.
I shook my head awkwardly. Wouldn't it be strange for the homeowner to leave to accommodate me while I was getting a blowjob?
“No, it's fine….”
Honestly, it wasn't fine.
The thought of Subin sitting right beside me and watching Chaerin and me engage in such lewd behavior made my face burn with embarrassment.
Chaerin paused for the briefest moment, then calmly took my cock into her mouth again and began working it with her tongue.
Only then did I realize one of the new common-sense rules of this world.
Whenever a man needed sexual relief, it had to be provided immediately, no matter when or where.
It was just as natural as a wife preparing dinner for her husband.
Though it was difficult for Subin to watch, it wasn't a serious matter to her.
It was simply that I, as a man, urgently needed sexual relief, and Chaerin was merely fulfilling that duty—a perfectly ordinary sight.
Subin barely showed any jealousy at all.
Only the slightest trace of envy passed through her eyes as she looked down at Chaerin's head.
Still, she must have been interested, because I could feel Subin sneaking glances this way even while pretending to focus on the board game.
-Smack, smooch, sluuurp.
Whenever Chaerin's mouth made an explicit, wet blowjob sound, Subin's body flinched. The tips of her ears were slightly red.
The thought of someone watching me receive a blowjob made something inside me begin to boil again.
Conscious of Subin's gaze, my body naturally tensed. That tension gave me a strange shiver, which amplified the pleasure until my cock swelled as though it might burst.
Chaerin immediately noticed the change in my cock and took it even deeper into her mouth.
My cock reached almost to her throat, but she didn't stop. Instead, she tickled the underside of my glans with her tongue, giving me even more intense stimulation.
I ejaculated deep in Chaerin's mouth before long.
-Brrrshhh!
Even though I'd had sex with the health teacher, the amount of semen I produced hadn't diminished in the slightest.
If anything, perhaps because of the taboo of Subin watching, I seemed to release more than usual.
“Mmph, gulp….”
After taking a mouthful of semen, Chaerin glanced at Subin for some reason, then swallowed it all instead of going to the bathroom to spit it out.
As though she were showing off the fact that she'd given me a blowjob.
Then she gave me a thorough cleanup blowjob, licking up every last drop of semen before finally pulling her mouth away.
“Phew….”
After completing her service, Chaerin let out a satisfied sigh. She casually wiped her mouth with the back of her hand as though nothing had happened, then returned to her original seat.
“So, shall we finish the board game now?”
The problem was me.
Even after ejaculating once, my erection hadn't subsided in the slightest.
On the contrary, the combination of Subin's gaze from beside me and Chaerin's saliva still coating my cock made it swell even harder.
There was no way I could put my pants back on like this.
I looked at Subin with my pants off, wrestling with an intense inner conflict.
Should I say this? What if she came to hate me? Maybe Subin wanted it too.
I felt I would regret it if I let this opportunity pass. In the end, I couldn't hold back and opened my mouth.
“Subin.”
“Yeah?”
“Do you want to… give me a cleanup blowjob too?”
At that moment, Chaerin's gaze locked onto me. I sensed a faint jealousy from her, but it wasn't that strong.
Subin's face turned as red as a tomato at my suggestion. She didn't reject it.
Instead, she gave a small nod with an expression that mixed joy and shyness, as though she were grateful I'd given her such an opportunity as well.
“Y-yes…!”
I remained standing where I was.
As though she'd been waiting for this for a long time, Subin approached me and knelt down without hesitation.
She shot Chaerin a quick glance as though checking her reaction, then shifted her gaze to my cock and swallowed nervously.
In a reverent, prayer-like kneeling posture, she gazed at my cock, still faintly coated with Chaerin's saliva.
My thick, long cock cast a shadow over her beautiful face.
The firmly erect glans nearly touched her neat forehead, while the base of my cock reached below the end of her tightly clenched jaw.
Subin's green eyes trembled faintly with awe, as though she were looking up at a massive pillar.
The sight of her entire face seeming to lie beneath the sheer presence of my cock alone made it impossible for me to suppress my desire to conquer her.
At last, Subin's cherry-like lips slowly parted and took my glistening cock into her mouth.
“Slurp….”
Those were the very lips that had been kissing me just moments ago, and now they were swallowing my cock.
That fact alone filled me with such intense excitement that I felt my head might explode.
“Mmph, lick, slurp….”
Of course, this was Subin's first blowjob, and she apparently hadn't properly practiced either, so her movements were far rougher and clumsier than Chaerin's.
Her teeth occasionally bumped against my cock, and her tongue movements were awkward as well.
“You're doing incredibly well for your first time.”
Even so, I didn't skimp on my praise as I stroked her soft blonde hair.
That was because I'd already realized how strongly Subin responded to praise.
As I'd expected, Subin visibly brightened whenever I praised her and tried even harder.
Her clumsy tongue movements gradually became smoother, and she tried to please me in her own way.
She no longer sucked the shaft; instead, she extended her tongue and meticulously licked away the saliva Chaerin had left behind, from the tip of my glans all the way to the base.
She probably hadn't intended it that way, but it felt like possessiveness—as though she wanted to erase Chaerin's traces from my cock and cover it with her own—which made me even more aroused.
Thus, surrounded by two beautiful women, I reveled in pleasure in someone else's living room for quite some time.
When the clumsy cleanup blowjob ended, I praised her once more, telling her she'd done incredibly well despite it being her first time.
And I sincerely thanked Chaerin as well, without forgetting to tell her how grateful I was for taking care of my needs.
Chaerin's expression softened a little, and she gave a tsundere-like reply: “Well, it's nothing.”
And so, the two women who had just taken turns giving one man blowjobs acted perfectly normally.
As though nothing had happened, they ate the fried chicken they'd ordered for dinner and finished their board game.
That night, when I returned home, my phone began ringing incessantly.
When I checked, it was a newly created class group chat. Everyone was chatting quite energetically.
When I sent a casual greeting, almost all my classmates greeted me warmly in return.
In the middle of that, I received a private message from Subin.
[Did you get home safely? I had a lot of fun today. See you tomorrow, Sihyeok.]
It seemed that, because Chaerin had interrupted the momentum of her confession, Subin intended to go back to being friends for the time being.
After exchanging a few brief messages with Subin, I found myself curious once again about the former ‘Kim Sihyeok’ as I looked over the countless contacts and messages accumulated on my phone.
Before going to bed, I set aside some time to slowly look through traces of his past.
The conclusion I came to after reading them was that he had been an utterly ordinary man.
He didn't like women as ordinary men did, and he had no sex drive either. Still, he sometimes ate with women or talked with them and received pocket money and gifts—the relationships amounted to exactly that.
There was nothing particularly special about him. What on earth had happened?
As I sat thinking about Kim Sihyeok, I found it troublesome that my cock kept getting hard as I watched Chaerin's ample buttocks while she cleaned the house beside me in dolphin shorts.
As always, I swallowed several pills the hospital had given me with water and fell asleep.
* * *
Subin's House.
Subin excitedly boasted to her mother about how much fun she and Sihyeok had had that day. Her mother had just returned from work at the hospital.
Her mother, Han Dan-bi, merely smiled affectionately and replied, “I see. Did you have a lot of fun?”
But deep in the night, after her daughter had fallen asleep, the atmosphere in her room was completely different.
With her beautiful blonde hair and youthful, elegant features, she could easily have passed for Subin's older sister.
Dan-bi, dressed in an elegant silk gown, took out a sleek laptop with no identifying marks.
Fingerprint. Iris. After passing through the dual biometric security, a cold blue interface appeared on the screen.
[Project M: Status Monitor]
[Subject under observation: KSH-073]
Complex graphs depicting Kim Sihyeok's vital signs and changes in his hormone levels filled the screen.
Han Dan-bi skimmed through the contents of the transmitted report with an impassive gaze, then typed a short entry into the confirmation field at the bottom.
[Evaluation: Sexual-impulse-related hormone response active. Prefrontal cortex activation related to aggression control within stable range. Maintain current drug regimen.]
Her gaze was cold and subdued as she pressed the Enter key. A dry sigh escaped her.
She closed the complex interface and opened a photograph of her daughter on the desktop.
A photo of Subin beaming with Sihyeok at her graduation not long ago filled the screen.
Her daughter's warm smile. As she stared at the photograph, her gaze wavered with conflicting emotions.
Across the street, the light in the window of Sihyeok's house went out.
‘If it’s for Subin’s happiness….’
She muttered softly.
“It can't be helped. I did my best.”
She turned off the screen and leaned back in her chair.
Beneath her closed eyelids, the face of her happily smiling daughter and the face of a man screaming in anguish surfaced simultaneously.