Pairing: Hybrid!Heeseung x Vet-Med!femReader
Genre:Enemies-to-lovers, domestic fluff, college AU
Synopsis: When the campus menace and notorious snack-thief Lee Heeseung gets caught in a downpour and sprains his ankle, his fierce hybrid survival instincts kick in. To your absolute shock, his arrogant facade completely melts, leaving you to deal with a deeply feverish, incredibly clingy hamster hybrid who refuses to let you leave his freshly built living room nest.
The hum of the library’s ancient AC unit was usually enough to drown out the existential dread of my third-year Veterinary Medicine coursework, but today, the universe had chosen a louder, more irritating soundtrack.
*Crunch.* I didn't even have to look up from my tablet screen, where a complex diagram of hybrid nervous systems was currently blurring together. The faint, sweet scent of honey-butter seasoning and the soft, distinct rustle of a plastic wrapper told me everything I needed to know.
"Are you actually serious right now, Heeseung?" I muttered, rubbing the bridge of my nose beneath my wire-rimmed glasses.
A shadow fell over my desk, and before I could react, a long, pale hand reached directly into my open tote bag. Soft, rounded, sandy-brown hamster ears poked out from a mass of messy black hair, twitching in absolute triumph as he snagged the family-sized bag of chips I’d bought to survive my midnight study session.
"You bought the good ones today, Four-Eyes," Heeseung drawled. He slid into the empty plastic chair next to me, stretching his ridiculous six-foot-one frame out under the cramped desk. He invaded my personal space with the practiced ease of someone who owned the place, a permanent, lazy smirk plastered across his face. "I'll consider this tax for letting you sit in my glorious presence."
"Your presence smells like cedar shavings and stolen property," I snapped, reaching across his chest to grab the bag.
Heeseung dodged instantly, hoisting the chips high above his head. Because he possessed the genetic irony of a tiny, hoarding rodent trapped inside the body of a varsity athlete, I had to lean completely across his lap just to swipe at the air. He looked down at me, his dark eyes sparkling with unadulterated mischief, his twitchy pink nose crinkling as he laughed.
"Want 'em? Come get 'em, Dr," he teased, his fluffy ears flattening playfully against his head.
"Give it back, you oversized rodent, or I swear to God I will swap your presentation slides for the seminar tomorrow with a forty-slide gallery of senior-citizen guinea pigs."
Heeseung paused, his ears drooping just a fraction. He knew I’d do it, too. Last week, after he hid my anatomy notebook in the vending machine, I had changed his phone’s alarm to a high-pitched frequency that only hybrids could hear. He hadn't slept properly for forty-eight hours.
"You're evil," he muttered. But instead of handing the bag over, he casually popped a chip into his own mouth, then reached down and stuffed one directly into mine to silence me.
Across the aisle, two guys from the agronomy department were already snickering into their textbooks, whispering something about us that I chose to actively ignore. This was our daily warfare, a predictable routine of bickering, stolen snacks, and mild property damage that kept us both awake through the grueling college semesters.
But the universe has a funny way of shifting the balance when you least expect it.
It happened on a miserable Tuesday afternoon. The sky had opened up into a torrential downpour, turning the campus walkways into a slick, muddy hazard zone. Heeseung, possessing the stubborn pride of a hybrid who refused to admit that his animal counterpart hated getting wet, had marched out of the science building without an umbrella because "hamsters don't do rain."
An hour later, as I wrapped up a grueling lab session and walked out into the damp, freezing drizzle, I spotted a slumped figure on the bench beneath a leaking awning.
It was Heeseung. The arrogant, smirking menace of the library was entirely gone. His clothes were soaked to the skin, his left ankle was visibly swelling through his sneaker, and his usually fluffy ears were completely plastered to his head, drooping miserably over his eyes. He was shivering violently. Because hybrids struggle significantly with thermoregulation when their fur or ears get wet, the cold was hitting him twice as hard.
"Heeseung?" I called out, rushing over.
He flinched, looking up with pale lips and glossy eyes. "Y/N," he croaked, looking utterly devastated that I was witnessing him like this. "I... I slipped on the moss. My ankle popped."
My cynical student brain wanted to throw a sarcastic comment his way, but the future veterinarian in me took over the second I saw him tremble. Without a word, I unzipped my duffel bag, pulled out my dry, oversized fleece hoodie, and draped it over his shivering shoulders.
He looked down, his cheeks flushing a faint, embarrassed pink. "No."
For the first time since I’d known him, Heeseung didn't make a snide remark. He just quietly let me hoist his heavy arm over my shoulder, his large frame acting as deadweight against mine as we slowly, painstakingly navigated the slippery sidewalk back to my apartment, which was thankfully just a block off-campus.
By the time I got him inside, stripped him of his soaking wet jacket, and got some ice on his sprained ankle, his high fever had kicked his hybrid instincts into absolute overdrive. When a hamster hybrid is severely sick or injured, their higher-level human reasoning takes a backseat to their base survival programming. For Heeseung, that meant one urgent, desperate necessity: nesting.
"Y/N..." he whimpered from the living room floor.
I walked out of the kitchen holding a bowl of warm broth and some anti-inflammatories, only to stop dead in my tracks. Heeseung had dragged every single pillow off my bed, my winter duvet, three throw blankets, and a pile of my freshly laundered clothes into a massive, circular fortress in the center of the room. He was curled up right in the middle of it, burying his face in the fabrics.
"The nest isn't right," he mumbled, his voice thick and congested. His nose twitched rapidly as he sniffed the air, his ears twitching anxiously. "It doesn't smell like you enough. I need... I need the green sweater. The one you wore yesterday."
I stared at him, completely stunned. The campus bully who spent his mornings throwing paper balls at the back of my head was currently begging for my laundry to secure his sick-nest.
"Heeseung, you're burning up. Take the medicine first," I said softly, kneeling at the edge of the blanket pile.
He watched me with wide, vulnerable eyes. Slowly, a pale hand reached out from under the duvet, his fingers gently catching the hem of my shirt and pulling me weakly toward him.
"I'm sorry," he whispered, a genuine tear pooling in the corner of his eye before slipping into the soft fur at his temple. "For stealing your chips. And hiding your books. I'm a terrible hybrid. You're trying to save lives and I'm just a menace."
The fever-induced guilt was making him look so incredibly small despite his size that my heart completely melted.
"Hey," I murmured, setting the bowl down and carefully crawling into the nest with him. "I bully you back, remember? I changed your laptop background to a hawk last month. We're even. But right now, you need to rest."
Heeseung let out a shaky sigh, the tension leaving his shoulders the second I sat beside him. Before I could move, his long arms wrapped securely around my waist, pulling me down into the center of the blankets. He buried his face directly into the crook of my neck, inhaling deeply.
"Stay," he mumbled against my skin. "Your scent makes it safe."
I couldn't leave even if I wanted to. He had effectively locked me in place, curling his long legs around mine like a giant, clingy rodent hoarding his favorite prize. His hot breath tickled my collarbone, and every few seconds, his incredibly soft ears would twitch against my cheek. As I carefully ran my fingers through his dark hair, avoiding the sensitive base of his ears, a low, rhythmic vibration started in his chest. It was a soft, content chattering—the ultimate sign of a hybrid who felt entirely safe and protected.
The next morning, the storm had passed, and bright sunlight filtered through the living room windows.
I woke up to find Heeseung’s fever had finally broken. He was still holding me tightly, but he was awake, staring down at my face with an expression so remarkably tender it made my breath catch in my throat. Seeing my eyes open, his ears perked up instantly, standing tall and fluffy.
"Morning," he whispered, his voice deep and raspy from sleep.
"How's the ankle?" I asked, shifting slightly in the pile of blankets.
Instead of letting me go, Heeseung just tightened his grip, hiding his flushed face in my hair. "Still hurts. I think I need to stay in this nest for at least another three days. Minimum."
I let out a soft laugh, poking his side. "Oh, really? The great Lee Heeseung wants to cuddle with Four-Eyes for a long weekend?"
He pulled back just enough to look me in the eyes, the familiar, playful glint returning to his gaze, though it was softened by something entirely real. His thumb reached up, gently brushing a stray strand of hair away from my glasses.
"I'll buy you a lifetime supply of honey-butter chips," he promised softly, his cheeks turning a bright pink. "And I'll let you study my hybrid reflexes all semester. Just... don't leave the nest yet."
I smiled, reaching up to gently scratch behind his sandy-brown ears, watching them twitch happily in response. "Deal, you oversized hamster."
Sorry, I know it's not what you guys asked for. 😞
