Over the next few weeks, I planned to put Mr. Lee through a series of tests to expose any hidden predatory behaviors. I would no longer simply watch him from a distance.

I had meticulously planned every interaction. Every word would be deliberate. Every reaction, carefully observed.

Child predators rarely expose themselves openly; more often, they reveal themselves through patterns—subtle boundary violations, favoritism, rationalizations, and a gradual erosion of professional distance.

So, I would give him opportunities. Opportunities to overstep. Opportunities to justify.

Opportunities to reveal who he truly was.

I would present myself as exactly the kind of target many predators seek out: lonely, rebellious, lacking supervision—emotionally difficult, yet secretly starving for attention.

If Lee Hyun-woo was guilty, instinct would eventually betray him.

I made sure to complete my math homework over the following two weeks, but I was deliberate in my errors. In some problems, I worked out the equation perfectly halfway, then introduced a subtle, plausible point of confusion. In others, I got the initial setup right but botched the final step. It was a calculated dance. I needed to look like a student trying his best, but lacking the fundamental foundation. In the Korean education system, a teacher’s pride is deeply tied to their students' effort—and I was effectively hacking Mr. Lee’s empathy.

At the end of the second week, it worked. As the bell rang for break and the classroom emptied, Mr. Lee called out.

"Ji-ho. Come here for a moment."

I sauntered over. My hair still hung long at the nape of my neck, deliberately defying his advice to cut it shorter. I scratched the back of my neck, affecting an air of impatience.

"I see you’re trying to get the work done," he started, his tone gentle, employing the classic pedagogical approach to criticism. "But you seem to be struggling with the core concepts."

I stared at him, keeping my face blank. I couldn't appear too eager. "Ne," I supplied flatly.

"I’d like you to stay after school today. I’ll put you through some extra exercises."

I held his gaze for a beat. "Okay." I turned and stumped off before he could say anything else.

My heart leaped with unprofessional excitement that I failed to ignore. Today I would execute my first test.

After school, I headed to the small tutorial room at the end of the hall. Usually, he coached a few struggling kids in here, but today, the room was empty. I dropped my bag, laid my head on the cool laminate desk, and closed my eyes, wanting to project an aura of bored uncooperativeness.

A few minutes later, the door clicked open.

"You're here!"

I grunted, sitting up reluctantly. Mr. Lee stood in the doorway, looking genuinely surprised that I had actually shown up. He rushed over, dropping the heavy math textbook on my desk with a soft thud.

"Great. Let’s start here," he said, flipping the pages eagerly.

I watched him, and for a second, my detective’s detachment slipped.

God, he was cute.

It was an inappropriate thought, one that had absolutely no place in an investigation, but I couldn't suppress it. His copper-brown curls looked incredibly soft, the kind of hair you just wanted to disappear your fingers into. His round glasses rested slightly low on his nose, and when he looked up at me, I was struck again by how small and youthful his face was. The lines and angles of his face were soft, with skin that flushed easily and a tiny, endearing mole just beneath his left eye. He didn't look like a strict head of discipline; he looked like a graduate student who got lost on the way to a lecture.

He moved to the chalkboard, chalk clicking rhythmically as he explained the foundational rules of algebra. He broke it down with the patience of someone speaking to a five-year-old. Every few minutes, he paused to ask for confirmation, his dark eyes searching mine to ensure I was following. When I deliberately took him back three steps to re-explain a concept, he didn't get angry. He just smiled that soft, encouraging smile and started over.

By the end of it, my conscience pricked me. I didn't want to be an asshole. I wanted to see him rewarded for his effort. So, after failing the first three sums and accepting his gentle corrections, I solved the fourth one perfectly.

His excitement was instantly contagious. "Daebak! Good job, Ji-ho," he smiled, actually shaking his fist in a small, triumphant pump.

I struggled to hold back my own smile, burying my face in my paper to hide it.

On the next and final question, I screwed up my face, tapping my pen against my chin as if thinking incredibly hard.

"Seonsaengnim, I’m stuck here," I said, pointing at the paper.

He hurried over to my side, leaning in close to get a better look at the challenge. His shoulder brushed my arm. A jolt of electricity shot up my spine.

"For this question," I murmured, keeping my voice low. "5x - (2y - 4x). Why does the 4x carry a plus sign after the bracket is removed?"

He had taught this rule at least ten times today, but without hesitation, he began to explain the sign distribution rules again.

I stopped listening to the math. I just listened to the soft, firm cadence of his voice washing over me. This close, I could smell him. It was a subtle, intoxicating scent—bright yuja and warm spice, grounded by the faint, clean hint of his daily sweat. His lips, hovering just inches above mine, looked incredibly pink and soft. His dark brown eyes, framed by those round glasses, were entirely focused on the paper, urging my attention to stray to his mouth.

The detective in me was screaming to pull back, to maintain the perimeter. It was totally unprofessional. I was supposed to be investigating him, not undressing him with my eyes. Instead, I leaned into him, inhaling deeply.

He froze. The chalk in his hand snapped.

Then, he backed away quickly, nearly tripping over his own feet.

"Ji-ho, d-don't do that," he stammered, his cheeks instantly blooming a furious red.

"I like your scent," I replied immediately, my voice smooth. "Is that a yuja undernote?"

"Ye-yes. I think," he replied, clearly flustered. He practically fled back toward the safety of the blackboard, adjusting his glasses with a trembling hand.

"It’s nice, seonsaengnim," I pushed, leaning back in my chair. "Can you bring me some tomorrow?"

"Absolutely not," he said, his voice pitching up an octave.

"Why not?" I asked dumbly.

"Because it’s inappropriate... I’m not allowed to gift you things; I’m your teacher. Do you understand?"

I pouted like an indignant teen and started drawing a random figure in my notebook, feigning anger.

"Let’s call it a day, Ji-ho. Read up on the sign rules, and we’ll pick up again next week."

"Next week?" I groaned, shutting my book with a sharp snap. "Jinjja? That’s too far away." I pushed off my seat, standing to my full height. My tall frame suddenly felt very intimidating in the small, quiet room.

He swallowed hard, taking a half-step back. "I told you math was fun," he said, trying to inject a sparkle into his eyes, though his voice wavered.

"It’s not just math that’s fun," I muttered, taking a slow step toward him.

His smile wavered, his eyes darting to the door. "What do you mean?"

"You, seonsaengnim," I said softly, holding his gaze until he was forced to look away. "You are fun."

I was intentionally blurring the lines.

Attention-seeking behavior in adolescents was not unusual, particularly in those with absent parents and a history of repeated school transfers.

If Lee truly believed I was a vulnerable seventeen-year-old becoming attached to him, his response would tell me everything.

Professional adults reinforced boundaries.

Predators exploited them.

He stood there, his mouth slightly open, completely unsure of what to say or how to reassert his authority. The silence stretched, thick and heavy with things neither of us was supposed to be feeling.

"Annyeonghi gaseyo," I called out with a bow, then turned to leave.

"Ji-ho."

I paused, looking back over my shoulder. His voice was quieter than usual.

Mr. Lee had removed his glasses, pinching the bridge of his nose. The flush hadn't left his neck.

"Don't say things like that," he murmured.

"Like what?"

A pained look flickered over his face. "Things that can be misunderstood... Don't seek attention in that way. I'm here to help you, Ji-ho, but there must be boundaries. Do you understand?"

There it was. Not encouragement. Not curiosity. A boundary.

"I value teaching you because you're my student," he added, his voice softening as he lowered his eyes back to the desk. "Nothing more. So focus on your studies instead of teasing your teacher, arasseo?"

The corner of my mouth twitched. Teasing. That’s what he chose to call it. Not flirting. Not seduction. Just teasing.

Interesting.

"Ne, seonsaengnim."

I turned and walked out. Through the glass pane of the door, I caught him standing still, watching me leave with a faint blush lingering on his cheeks.

I let out a long breath in the empty hallway. This was a dangerous game—and the worst part was, I was no longer sure who was testing whom.