The following day, my mind was a total, unmitigated mess.

I couldn’t keep my thoughts from wandering back to Mr. Lee. The image of his face, wrecked and flushed with pleasure, was burned into my retinas. But far more distracting was the aftermath—the way he had folded in on himself right after his release, burying his face in the pillows and sobbing. His small shoulders had shaken with a grief so heavy it felt like it was crushing him. My heart lurched in my chest just thinking about it. It wasn’t just raw lust anymore; it was a deep, unsettling ache that was severely compromising my objectivity.

I sat at the back of the classroom, my long legs stretched out under the desk, watching his completely oblivious face as he tried to explain Calculus: Limits and Continuity to the class.

The air in the room was suffocating under the heavy pressure of the upcoming Suneung (CSAT). The other students were taking notes furiously, their faces pale with exhaustion, but Mr. Lee was in his element.

I watched the way he pushed his wire-rimmed glasses up the bridge of his nose with his index finger—a habitual, endearing tic whenever he paused to scan the room. He crossed his arms across his chest, the crisp white fabric of his dress shirt pulling tight. It revealed surprisingly toned forearms underneath.

I know exactly what those arms feel like wrapped around my neck, I thought, a dark, involuntary smirk touching my lips.

Focus on the job, I scolded myself, digging my pen hard into my notebook.

He liked a student. Me. But he hadn’t actually made a move in real life. His yearning was trapped entirely in his own head.

Then again, he was likely being cautious because of strict societal boundaries. In South Korea, the hierarchical dynamic between teacher and student is heavily scrutinized; a single rumor, even if completely false, could instantly ruin a teacher's career, destroy his social standing, and lead to immediate dismissal. He was terrified of crossing that line. If I wanted to pull him down, I had to gain his absolute trust, break down his psychological defenses, and lure him into acting on his desires.

Throughout the period, he didn’t avoid me. In fact, he addressed me with the exact same polite, formal distance as everyone else, maintaining the strict boundary expected of a Korean educator.

"Kang Ji-ho," he said, tapping the chalk against the blackboard with a sharp clack-clack. "If the limit of as approaches does not exist, what does that tell us about the continuity of the function at that point?"

I sat up straight, smoothly shifting into the role of the reluctant yet improving student. "It tells us the function is discontinuous at , seonsaengnim," I said, pausing to pretend I was thinking it through. "Which means it’s a non-removable discontinuity."

Mr. Lee’s eyes lit up with genuine pride and warmth. "Correct. Excellent deduction, Ji-ho-ya. Good job."

My heart lurched at his praise.

Dammit. I have it so bad for this man.

At least his normal behavior confirmed he was totally oblivious. To his drunken, hazy mind, the man who brought him home was just a mysterious, masked stranger from a city club.

To keep his thoughts completely diverted, I had left a trail before slipping out of his apartment. I wrote my personal burner number on a piece of scrap paper on his desk:

Thank you for taking care of me last night. I had fun. Call me.

– Do-yun.

I had used my real given name, Han Do-yun, shortened to just Do-yun. It was a calculated risk.

What the hell am I doing? I thought, rubbing my temples as the dismissal bell rang.

I'm acting like a love-struck teenager.

Maybe I've stayed in this delinquent character too long.

Or maybe I'm just losing my mind.

Yet, as I watched him pack up his chalk and erasers, Mr. Lee seemed in surprisingly good spirits. He was humming softly under his breath, his steps light, a faint, secret smile playing on his lips. Was he happy about the note? Was he secretly debating whether to text "Do-yun"?

A sudden spike of jealousy surged through my chest.

What the fuck? We're the exact same person, I reminded myself. I really am going crazy.

Suddenly, the sharp rap of a wooden ruler against the teacher's podium cut through the rustle of packing bags. Our class monitor, a fiercely organized girl named Park Soo-jin, stood up at the front of the room.

"Attention, everyone!" she announced, her sharp voice instantly silencing the classroom. "I have an announcement regarding our senior retreat. The principal has officially approved our two-night, three-day trip!"

A collective gasp swept through the classroom.

For half a second, nobody moved.

Then the room exploded.

Cheers erupted from every corner. Desks rattled as students slapped their palms against them. Someone at the back actually jumped out of his chair. A few girls squealed, while the boys started talking over one another about hiking, food, cabins, and who would share a room.

The exhausted third-years had been living under the weight of the Suneung for months. Mock exams. Private academies. Late-night study sessions. University applications.

For the first time in weeks, nobody seemed to care.

"Ya! Quiet down!" Soo-jin called over the noise.

Nobody listened.

She laughed and raised her clipboard above her head.

"I said quiet down!"

The noise slowly died, though excited whispers continued to ripple through the room.

Soo-jin looked down at her clipboard.

"We'll be heading to Baekun Mountain Resort next Friday. The school wants you to have some time to relax before the final mock exams, so there will be hiking and team-building activities."

Another cheer broke out.

"And before anyone asks, yes, you'll have free time in the evening."

That nearly started another riot.

"Jinjja?"

"Are we staying overnight?"

"Who are we sharing rooms with?"

"Can we bring our phones?"

Soo-jin shook her head, laughing.

"One question at a time. Departure is eight o'clock sharp from the school gate. If you're late, the bus will leave without you."

The room erupted again.

I barely heard the rest.

Baekun Mountain Resort.

My pulse kicked.

A school trip meant long bus rides, shared activities, late evenings and students moving around without their usual routines. Teachers would be distracted. Supervision would be divided between staff members. And the mountain resort was far enough from Seoul to make surveillance harder.

More importantly, Mr. Lee would be there.

I glanced toward the front of the classroom.

He was helping Soo-jin pass out the permission slips. His copper-brown curls caught the afternoon light as he smiled at the students crowding around his desk.

He looked relaxed.

Happy, even.

I watched him for several seconds.

My heart taking off like a runaway freight train.

This could be exactly what I needed.

A controlled environment.

More opportunities to observe him.

More opportunities to test him.

And if the evidence I'd been looking for existed, a trip like this might finally expose it.

I folded the permission slip and slipped it into my notebook.

I looked down at the permission Soojin placed on my table.

The investigation had just become much more interesting.

I knew I was going to do the worst. I was going to seduce him there. I was going to break every last one of his defences, and finally, I was going to get the truth.

That evening, I sat in the dark, my heart in a flurry. My real, cell phone was in my hand. I only put the phone on at night to follow up on my real life, leaving it off and at home all day when out, using a different phone for my student persona Hung while at school.  Now I wondered if he’d texted me and what I should do if had. How I would feel if he hadn’t.

 I turned it on and the screen immediately lit up with as messages flooded in, several from my secretary checking up and… 

Yes! 

Two messages from an unknown number, my heart did a stupid, unprofessional flip.

4.30 pm: Hi, it’s me from last night. Sorry I was a burden, taking me home and all. I’d like us to hang out some other time. Tried calling you but your phone is switched off. Call me.

4.55 pm: Hi again, hope you got my last message. Just checking. Call me.

So needy, I thought, a smirk touching my lips.

I set the phone down and tapped the keyboard, bringing up the live feed from my hidden camera in his tote bag. The audio and video synced perfectly. 

Mr. Lee was still at school, sitting alone in the general staff room. The setting sun was filtered through the plastic window blinds, casting striped shadows across his desk. The room itself illuminated in fluorescent light, looked cluttered, his desk stacked high with textbooks and yeon-byeok. The faint, tiny sound of the wall-mounted AC unit hummed through the camera’s microphone. He was sorting through a stack of mock exam papers, his copper hair ruffled, his eyes looking a little tired. But he was focused.

Intermittently, however, he would pause, reach for his phone, check the screen, look slightly disappointed, and then refocus on the scripts. He rubbed the back of his neck, letting out a soft, frustrated sigh that the mic picked up perfectly.

 Was he waiting on my call? I thought, shaking my head. Too cute.

I hit the call button on my phone.