BUTTERFLY
f. reader x Yeon Si-eun
genre: established relationship, full fluff, college!au.
wc: 2.4k
warnings: aged up characters, Nabi means butterfly in korean, Si-eun being a sweet cat dad, that's it, that's your silly boyfriend.
synopsis: Si-eun never asked for a cat. But when a tiny black kitten curls up in his arms, he seems to change his mind pretty quickly.
a/n: Divider made by @saradika-graphics I made this as a way of coping with the fact that I couldn't adopt a pretty kitten that I wanted, when I finally could get her, she was just with somebody else.... I hope she has a great life because she is really lovely. This was requested by doremichann
You had been thinking about that cat for at least two weeks.
It all started with a cardboard box left in front of your veterinary school building. It was common for people to abandon animals there. Somehow, people expected that because of the vocation you had chosen, you could take care of every animal in the world and every situation involving them. The senselessness of that idea made you anxious, but you knew at this point in your degree that it was useless to fight against common sense.
Most of the time, you managed to absorb the number of animals abandoned there. Some were adopted immediately, others stayed at students' homes temporarily until they found a permanent home. As wrong as it was to accept that situation, you eventually became those people's hope—and indeed, you gave homes to those animals. It would simply be too hard to ignore a defenseless being in need, and that only contributed to raising the expectation even more that you were immaculate saviors.
You, however, were anything but part of that group of saviors.
Yes, you contributed financially with donations when you could and shared the adoption campaigns, but since your building didn't allow pets, you never felt like you were really helping. Until eventually, that day arrived.
The message group of people who participated in animal fostering wouldn't stop making your phone vibrate during the day. That sometimes happened when an animal couldn't find a home and needed one immediately. It was very common in cases of older animals or those in situations requiring extra care due to illness. But to your surprise, that wasn't the case.
It was a kitten. Black with tiny white details. The same one you had been following for days and that, for some reason, had captivated you more than anyone in that active adoption and donation group.
You felt very tempted to adopt her several times, but you knew it would be impulsive to take her only to have to give her back if your landlord found out about her existence, so you contented yourself with looking at a few photos fondly and accepting that eventually she would find a permanent place.
However, a problem arose, and the person who was going to take her couldn't provide that support anymore, returning the cat to one of the students in the group. Apparently, she had a bad adaptation with the willing adopter, who already had another older cat, and the animals almost got into a serious fight. Now, for safety reasons, she had been separated from that cat and, consequently, was left without a new home.
Your heart tightened more than it ever had in all the time you'd been part of the group. It wasn't just about the cat's situation. It was the fact that you had wanted her from the beginning. In some way you couldn't explain, the two of you had formed a connection. You could imagine yourself with her, sleeping with her, hearing her purr as you studied and she rested on your lap. You could almost smell her.
You almost… Ah, screw it! You thought. And in a moment of total impulse, you volunteered to take her. Your problems with the landlord would have to wait.
[…]
You were stroking the still‑nameless cat's fur as she rubbed against your hand and purred, when finally the impulsiveness of your action came to the surface.
Honestly, you didn't mind keeping her as a big secret so much, but that secret didn't depend entirely on you—it went far beyond that. How could you guarantee she wouldn't raise any suspicion when you were away at college? It wasn't as if you could take her in your backpack or monitor her 24 hours a day.
No, you couldn't imagine going back on your decision, but you also couldn't stop cursing your own lack of restraint. No, you couldn't blame the cat's sweet eyes or the way she meowed at you so affectionately. You only had yourself to blame, and honestly, yourself to find a more viable solution. And no, giving her back to the adoption group—which would feel like a second rejection to her—was not among the options.
You took a deep breath, trying to find a way out, any way out.
Until something you had never considered came to mind. Or rather, someone.
Yeon Si-eun.
[…]
Your boyfriend stood before you after opening the door of his apartment, staring at you as if there was a bomb in your arms instead of a cat. It was a little hard to tell what he was thinking, mainly because you had called saying you needed to see him urgently, and suddenly you were at his doorstep with a large bag in one arm and a kitten in the other, curiously staring back at him.
Si-eun knew better than to bombard you with questions, especially while you were still in the hallway of his building, so he just made space for you to enter and closed the door behind you.
Still in silence, he guided you—though he didn't really need to, since you already knew every corner of that apartment very well—to his room, where you sat down on his bed. The kitten still in your lap while you set the bag on the floor.
"I imagine the urgency has to do with…" Your boyfriend gave you the cue to start explaining.
"She doesn't have a name yet."
"Right."
You didn't know exactly why you had said the cat didn't have a name, as if that was what Si-eun was asking. You knew that wasn't what he wanted to know. He wanted to understand what his girlfriend was doing here in the middle of the night with a kitten and a giant bag.
Even with all the curiosity in the world, Si-eun didn't pressure you to say everything immediately, and you couldn't help but notice how his gaze kept drifting toward the cat. You never tired of admiring your boyfriend's expressive eyes, but that wasn't what caught your attention about them now. They were staring intently into the kitten's eyes on your lap. Both the cat and your boyfriend seemed to be studying each other—the two of them with the most beautiful eyes in the world.
You almost felt like an intruder in the situation.
"She won't bite," you said, breaking the spell. "She's very calm."
Si-eun blinked first. Of course he did.
"You brought her here because your building doesn't allow pets," he stated. It wasn't a question.
You nodded, hugging the kitten against your chest as if she could protect you from the conversation. "I'm not going to ask you to keep her forever. Just… for now. Until I figure out what to do. Until I find a way."
He didn't answer immediately. Instead, he approached—one slow, calculated step—and sat down on the edge of the bed, beside you. Not too close, but close enough for you to feel the warmth radiating from his arm. The cat turned her head to stare at him again. And then, with an audacity that only a kitten could have, she stretched out her neck and sniffed his fingers.
Si-eun didn't move.
She sniffed for a few more seconds, blinked slowly—which you knew was a sign of trust in cats—and then rubbed her cheek against the tip of his index finger.
Your heart leaped.
Si-eun finally looked away from the cat and fixed his gaze on you. "She stays," he said, simple as that—simple like he always was with you. "For now."
The relief that flooded your chest was so overwhelming that you almost cried. "Si-eun-ah, thank you so much, I swear I'll figure this out as soon as possible—"
As you were still trying to plead your case, Si-eun got up, went to his closet, and took out an old t‑shirt. He folded it into a perfect square and placed it on the floor beside his bed, as if he were setting up a miniature campsite.
"Is that for her?" you asked, incredulous.
"She needs a place to sleep." But Si‑eun quickly added in his classic rational tone, "But I'm not sleeping with her either."
You almost laughed. "She's not going to steal your bed, Si-eun-ah."
Your boyfriend just looked at you with that expression that said "I'm not taking that risk" without having to open his mouth. The cat, however, had already lost interest in him and was now nestling deeper into your lap, her tiny eyes slowly closing.
"How cute. She's sleepy," you murmured, stroking her head. "That was a lot of excitement for one day."
Si-eun watched the scene for another moment, then got up from the bed. "Are you sleeping here too?"
The question was practical, not an invitation. He was already grabbing an extra pillow from the closet, as if your presence there was already a foregone conclusion. Because it was. That was how it worked between you.
"If it's not a bother…"
"It's not." He tossed the pillow onto the bed, next to yours. "But the cat stays on the floor."
"Si-eun-ah, she's tiny…"
"On the floor."
You sighed, but smiled. He was already pulling off his hoodie, leaving himself in his usual black t-shirt, and flopped onto the bed beside you with a low grunt. The cat meowed in protest at the movement but didn't open her eyes.
You didn't dare argue with your boyfriend since you were already asking too much of him. He wasn't mistreating the cat or anything, and not in a million years would he ever do that. You could only respect the boundaries he would set for taking care of her. Even so, something inside you felt that this situation wouldn't stay that way: you knew Si‑eun's soft heart better than anyone.
Adjusting your position in bed, turning your back to your boyfriend, you looked at the kitten one more time as she rested at the floor, on top of Si-eun's folded shirt, and then you finally felt relaxed enough to rest.
[...]
The next morning, very early, since you and Si‑eun had college, you both woke up to a surprise: the cat had climbed onto the bed and nestled herself between the two of you, sleeping soundly. She yawned, showing her pink tongue, and then started purring loudly. The kitten stretched, sinking her tiny claws into the blanket, and then turned to stare at Si-eun up close. He stared back, motionless.
"Good morning," you said, still sleepy.
"She was purring in my ear." His voice was rough with sleep. "For almost half an hour."
"And you didn't move?"
"She was sleeping."
Your heart melted. "You're an idiot, Yeon Si-eun."
He frowned, confused. "Why?"
"Because you pretend you don't care, but you do."
He didn't deny it. Instead, he sat up in bed carefully so as not to fully wake the cat—but she was already awake and meowed, demanding attention. Si-eun hesitated for a second, then slowly ran one finger between her ears. The purring grew louder.
"She's going to need food," he said, switching to practical mode. "And a litter box."
"I brought everything in the bag."
"Right." He got up. "I'll make coffee."
And he left, leaving you and the cat in bed. You weren't sure if he was running away from the situation or just being himself. Probably both.
[…]
Over the next few days, you instructed Si-eun on the best ways to take care of the cat, and he sent you photos and videos daily, along with descriptions of how the day had gone. It was a funny ritual, but you couldn't help finding it adorable. Even though your boyfriend wasn't obligated to be so dedicated given all his commitments with his own college, he still made an effort to keep you informed of everything.
Eventually, however, you noticed that over time, the messages became more frequent and the descriptions less distant, as if Si-eun was actually starting to see this as more than just another task.
Ever since you had left the still‑nameless kitten at his apartment, you hadn't been able to return because you were in the middle of a chaotic exam week. But now that week was over and you could finally breathe a little, it was time to pay your boyfriend another visit.
[…]
When you arrived at the apartment, Si-eun opened the door with the cat in his arms. She was curled around his arm like a baby, her front paws hanging down and her little head resting against his chest. He didn't say anything — just made space for you to enter.
"She doesn't want to get down," he commented, as if it were a technical analysis.
"And you don't want to put her on the floor," you teased, laughing.
Your boyfriend didn't answer. He just walked to the sofa and sat down, adjusting the cat on his lap with a care you rarely saw in him. She was purring like a little engine.
"She has a name now," he said, looking away. "It's Nabi."
"Nabi? Why Nabi?"
He was silent for a second, running his fingers slowly along the cat's back. "Because she's black. And small. And…" He hesitated. "Black butterflies are rare. When they appear, it's a sign. She appeared out of nowhere. In the middle of everything else."
Your heart tightened. He wasn't just talking about the cat.
"And you think she's a sign?"
"I don't know." He stared at the kitten, who was now closing her eyes in pleasure. "But she's not leaving."
"What?"
"She stays." His voice was firm but low. "Permanently. If you want. I've already decided."
You were speechless. That wasn't how you had agreed things would go. It was supposed to be temporary, just until you sorted out the situation with your building. But there was Si-eun — the same Si-eun who didn't like unexpected things, who planned everything, who rarely opened up — offering a permanent home to a kitten he barely knew.
"Are you sure?" you managed to ask.
"She's already adapted. It wouldn't make sense to take her away now." He shrugged, as if it were pure logic. But you knew him better than that.
"Si-eun-ah…"
"She likes me." He finally looked her in the eyes. "And I… don't mind her staying."
"You don't mind?" you repeated, laughing softly.
"That's what I said." The tips of his ears were slightly pink. The cat meowed, demanding more affection, and he immediately obliged.
You sat down next to him on the sofa, leaning your head against his shoulder. "You're in love with her."
"She's a cat." He answered immediately, as if nurturing that feeling for an animal didn't make sense.
"And you're hopelessly in love."
Si-eun neither confirmed nor denied it. But when the cat meowed softly, your boyfriend cracked a small smile. Nabi was home.
