After discovering that my sworn enemy was an incubus, I threatened him.

"Marty, as long as you let me touch your tail, I'll keep your secret."

Marty was both ashamed and furious, but in the end, with his face burning red, he still shoved his tail into my hand.

Biting his lip in reluctant humiliation, he said, "We agreed—only once a day. Not a single touch more."

But later, the very man who had insisted on "only once a day" knelt on the floor, crying as he begged me to touch it again, just one more time.

The moment the instructor shouted "Dismissed," Marty Scott bolted from the formation as if sprinting the hundred-meter dash.

His whole body looked like it was overheating—face flushed, breath rushed, movements frantic.

Watching his hurried retreating figure, I remembered what my godmother had told me that morning before I left the house.

"Olivia, Marty hasn't been acting normal lately. He looks exhausted and out of sorts. Help me keep an eye on him at school, okay?"

After reporting to the instructor, I chased after Marty.

At first, I thought he was just running to the restroom—but instead, he turned straight into the small wooded area on campus.

As everyone knows, the "little woods" at the university is never exactly an innocent place.

No wonder Godmother said he'd been acting strange lately. Turns out, he'd been secretly dating someone.

By the time I reached the woods, Marty was already gone.

Since when could he run that fast? If I'd known he had this kind of speed, I would've petitioned to have him sent to the Olympics to win glory for our country.

At first, I could still follow the footprints on the ground and tell which way he'd gone.

But the deeper I went, the lighter the footprints became—until they vanished completely.

What connected to the last of his footprints was a neat, smooth sliding mark.

It looked like… a snake's tail.

Yes. A snake's tail.

Holy crap.

Such a thick snake tail.

Staring at the trail on the ground—about as thick as my own thigh—I thought of how Marty's footprints had abruptly disappeared.

I clapped a hand over my mouth, eyes wide.

Had Marty been eaten by a python?!

If a python ate him… it probably wouldn't eat me, right?

Just as I was about to cry from panic, I heard urgent, restrained panting coming from the bushes a few meters away.

From the sound of it, whoever it was was in serious distress.

This voice… why did it sound so familiar?

I moved closer toward the source and could almost confirm the voice belonged to Marty.

But the sound was kind of…

My face flushed instantly.

Was Marty crazy? He had no shame, but did he expect a girl to have no shame too?

Huh? Wait.

Something was not right.

I listened again.

It sounded like… there wasn't any girl's voice at all.

Damn it! If I kept listening, I'd be overheating too.

I was about to leave when Marty's impatient, slightly tearful voice came from the bushes.

"Mom… I think I've awakened as an incubus. I'm so hungry right now, and I can't pull my tail back. What am I supposed to do…?"

Those few short sentences made my brain blue-screen on the spot.

Incubus? The kind of incubus I was thinking of?

Unable to suppress my curiosity, I walked straight toward the bushes.

I just didn't expect that… by doing so, I'd end up discovering Marty's earth-shattering secret.

…

Inside the bushes, a thick, black snake tail was coiled beneath Marty's body.

His eyes were red as he anxiously, desperately gripped his camouflage uniform, trying to cover the place where the snake tail connected to his human body.

But no matter how hard he tried, he couldn't hide it—the black scales at his waist shimmered faintly, and the tail was fully exposed.

I pushed the branches aside, and Marty followed the sound of movement and looked over.

Our eyes met.

Those pitch-black eyes immediately turned evasive and flustered. His lashes trembled, and the rims of his eyes—which had only been faintly red a moment ago—were now brimming with tears.

"Don't… don't come closer. Olivia, stop looking at me."

He raised his hand to stop me, his stammering voice seemingly forcing down some strange, turbulent emotion.

I wasn't the kind of person who liked to take advantage of someone in a vulnerable state.

I couldn't stop myself when I saw Marty with reddened eyes, practically begging me.

Every step I took toward him, he retreated an inch.

But Marty wasn't human anymore. He was an incubus.

So, technically, I wasn't taking advantage of him.

Besides, he'd bullied me plenty of times before. Teasing him a little now wasn't going too far, was it?

"Marty… so you're actually a male incubus."

His face turned so red it looked like it might bleed. With a trembling, tearful voice, he begged me not to come any closer.

The more he resisted, the more I wanted to move closer.

Served him right for always bullying me. Now it was my turn.

I licked my lips and crouched beside him.

"Marty, stop backing up. If you keep moving, your tail's really going to be exposed. Just stay still and let me take a good look—what's the difference between an incubus and a human, huh?"

A lazy smile tugged at the corner of my mouth as I spoke, and my hand moved on its own, brushing over his tail.

It felt cool to the touch. Honestly, it was like the ultimate heat-relief tool during military training.

Marty's tail jerked violently.

But since he'd only just awakened as an incubus, he was too weak to resist any of my movements.

Clenching his teeth, he looked like someone who'd been terribly wronged, red-eyed as he warned me, "Olivia, I'm only weak temporarily! I'm warning you, you'd better take your hand off my tail. Otherwise, once I recover, I will—"

I tightened my grip around his tail.

His voice cut off instantly.

His face flushed bright red. He covered his mouth, looking like he was about to die of shame.

I lowered my gaze to his tail that had actively coiled around my palm, then tilted my head and smiled at him.

"Will what? Why do I feel like your tail really likes me?"

"OLIVIA!" Marty looked like he was about to cry.

And somehow… that made me want to see him cry even more.

Just thinking about it felt thrilling.

All the defiance drained from him in an instant. A clear, crystalline tear dropped heavily onto the back of my hand.

He grabbed my wrist, his black eyes shimmering with tears as he stared at me, almost pleading. He looked like a delicate glass ornament that would shatter at the slightest touch.

His voice shook so badly it barely sounded like his own.

"Olivia… I'm begging you, okay? Stop teasing it."

"Then admit it. Admit you were wrong to bully me. And say you're sorry."

He took a deep, shuddering breath, the reluctance screaming in the silence. Finally, he broke. His knees hit the floor, and the words spilled out with his tears, "I'm sorry… I'm sorry, Olivia. You're right."

…

Because I'd been away from the group for too long, the instructor brought the other students to look for us.

Someone headed toward the wooded area.

Even though I really wanted to keep bullying Marty, he was still stuck in the human-body–snake-tail form.

If other people discovered his identity as an incubus, he'd definitely be treated like a monster and taken away by researchers for experiments.

I didn't want him to be taken. I hadn't finished playing with him yet.

"Marty, hurry up and pull your tail back in! Someone's coming this way."

Marty sighed and looked down at his tail, completely helpless.

"I'm really hungry. I don't have the energy to control my form. I can't pull it back."

I searched myself and only found a small piece of chocolate.

I stuffed it into his hand. "Hurry and eat it."

He shook his head. "Human food can't satisfy an incubus."

"Then what are you supposed to eat?"

I glanced around. All there was were trees and grass.

Oh. And me.

He couldn't be planning to eat me, right?

But in the very next second, Marty's ice-cold snake tail coiled tightly around my arm.

Before I could react, he yanked hard.

My whole body fell straight into his arms.

The violent movement alerted the nearby students.

Someone shouted loudly, "There's movement over there!"

A rush of hurried footsteps followed.

I braced both hands against Marty's chest, and our eyes locked.

"Olivia…"

The instant Marty said my name, his pupils contracted sharply. Then, the inky black of his eyes slowly turned into a bewitching, dark emerald green.

My mind went blank. All I felt was a warm, wet touch against my lips.

By the time I came back to my senses, Marty had already returned to a normal human form.

He sat on the ground, calmly straightening his clothes.

I was still under the lingering influence of the incubus's charm when his voice drifted to my ears, half-smiling, half-mocking.

"Incubi don't eat chocolate. Incubi eat 'people', especially bad women like you who take advantage of others."

…

The fact that Marty was an incubus was known only to his parents and me.

I searched online and discovered that there were actually many shapeshifting beast-humans in this world.

Normally, they lived in human form.

And in general, beast-humans had the same social status as humans, so few people bothered to distinguish between them.

But beast-humans with incubus bloodlines were different.

Incubi bewitched hearts. They used their supernatural abilities to seduce and charm humans.

Then, through special methods, they obtained energy.

Some humans, unable to hold firm to their hearts, often betrayed their lovers under an incubus's influence.

Because of this, the Enforcers had set rules: any beast-human who awakened an incubus bloodline had to sign a master–servant contract with a human or an ordinary beast-human within six months of awakening.

Otherwise, once discovered by the Enforcers, they would be taken back to a research institute.

There, they would undergo an "incubus bloodline purification" program.

Bloodline purification was an extremely painful process. Many succubi couldn't endure it and died during the procedure.

Once the contract was signed, the incubus could no longer charm anyone except their master.

They had to remain eternally loyal to their master.

Reading this, my heart began to itch.

My mind automatically filled with the image of Marty crawling at my feet, red-eyed, calling me "Master" in a trembling voice.

The more I imagined it, the more excited I became.

…

Ever since discovering that Marty was an incubus, I'd wanted to coil his tail every single day.

I used to be terrified of snakes. But now, I thought snakes were pretty cute.

Especially Marty's snake-like tail—one touch and he'd blush.

He was a baby incubus who clearly wanted me to touch him, yet forced himself to say no while starving.

Just like now—after the instructor dismissed us again, Marty sprinted out of the formation.

Looking at how red the tips of his ears were, I knew he was hungry again.

I chased after him.

This time, he didn't go to the woods.

He turned into the teaching building instead.

When I found him, he'd already shifted into his human-body–snake-tail form.

Marty was curled up in the corner of a classroom, staring at his pitch-black tail in despair and helplessness.

When I pushed the classroom door open, he was holding an inhibitor, searching for a place to inject it.

At the sound of the door, his hand jerked hard in shock.

The syringe fell to the floor and rolled right to my feet.

I picked up the syringe from the ground and turned around to lock the classroom door.

After the lock clicked into place, I held the syringe and slowly walked toward Marty.

The noise of the hallway was sealed outside.

Inside the classroom, only Marty and I remained, staring at each other.

As I slowly pushed the air out of the syringe, I stepped forward, bit by bit, until he had nowhere left to retreat.

He pressed both hands against the white wall behind him, his whole body on high alert.

"Olivia, you… don't come any closer! Are you trying to take advantage of me again while I'm weak?"