ℒ𝒾𝓁𝒾 @lilissweetdiary - Tumblr Blog

May 6

wait what if mc accidentally sent sebastian a love letter. like they were trying to write down their feelings and it just got sent by a helpful roommate by mistake

Love Letter | Sebastian Sallow x Reader

I HOPE YOU ENJOY ANON! I really had a great time writing the love letter, UGH that got me right in the heart ;.;

Words: ~3,900

Tags: Reader Insert, Female MC, No Y/N, No Hogwarts House, Drama, Fluff, Romance

Sebastian,

Witch Weekly says that writing down your feelings is supposed to help. That if you’re in love with someone you can never have, you should put it all down on parchment, let it spill from your heart like ink onto a page. Then, once it’s written, you can crumple it up, set it on fire, or hide it away where no one will ever find it.

I suppose it’s meant to be cathartic. A way to lighten the burden, to lessen the ache. But I know better.

Because no matter how many words I pour onto this page, no matter how many times I try to convince myself that this will fix something, I already know the truth.

There is no fixing this. There is no untangling my heart from yours.

I will love you until the day I die.

It feels embarrassing to even write that, like I’m some sappy, lovesick fool. But I suppose that’s exactly what I am. And who cares, really? No one is ever going to see this.

No one will ever know how deep this goes but me.

How have you never noticed, Sebastian? You’re supposed to be so sharp, so quick-witted, always a step ahead of everyone else.

But the truth is I’ve loved you since fifth year, since the moment we met.

Since the day you smirked at me like you already knew all my secrets, like you had me all figured out before I’d even said a word. You were infuriating from the start—sharp-tongued, arrogant, always so bloody sure of yourself. You challenged me, teased me, riled me up just to see me snap.

And I never stood a chance.

Somewhere along the way, your laughter became my favorite sound. Your voice became my comfort. Your presence became home.

I know you—in a way I don’t think even you do. I remember everything.

The way you take your tea, strong and almost disgustingly sweet, like you’re trying to cover up the bitterness with reckless abandon.

The way you tilt your head when you’re about to say something infuriatingly smug, that damnable smirk already forming before the words have even left your mouth.

The way your brow furrows when you’re deep in thought, when you think no one’s watching.

The way your hands twitch when you’re holding back, itching to reach for your wand, to fight, to protect.

The way you bite your lip when you’re trying not to laugh.

The way your eyes—Merlin, your eyes—burn with every emotion you try to hide. You think you're so clever, so unreadable, but I see it all. The mischief, the fire, the frustration, the fleeting moments of doubt you’d never admit to. They undo me. Every damn time.

And I’ve tried, Sebastian.

I’ve tried to love someone else.

I’ve been with other boys. I’ve gone on dates and smiled at the right moments, I’ve listened when they talked, I’ve let them hold me. And I wanted to feel something—I tried to feel something.

But none of them were you.

I could no sooner remove you from my heart than I could carve it from my own body.

You are in me. In every breath, in every thought, in every moment I spend wishing things were different.

And I have long since resigned myself to the reality that this is how it will always be.

You are my best friend, and that is more important than my feelings. It has to be. Because if I ever told you—if I ever let this slip—I don’t think I could bear the consequences.

So I stay quiet.

And at night, I stare up at the canopy of my bed and let myself think about all the things I will never have.

I think about you. I think about what it would be like if I were braver. I think about how you’d react if I kissed you.

Would your eyes go half-lidded, hazy with something slow and molten? Would you pull me close, pressing me against you, against something solid and warm? Would you let me run my hands through your hair, feel the softness of it between my fingers?

I wonder how you’d taste. If your mouth would be all heat and urgency, if you’d bite my lower lip just to make me gasp. If you’d whisper my name against my skin like you’ve always known it was meant for your lips.

Would you let me have you?

I think about it at night, when it’s late and the world is quiet and I’m alone with nothing but the ache of wanting you. I press my face into my pillow, close my eyes, and let myself pretend—just for a little while—that you want me, too.

But it doesn’t really matter. Because I’ll never know.

And I know I am eighteen years old, and older people love to say that teenagers don’t know what love is. That we’re naive, foolish, that we think we’ll feel this way forever when really, it’s just a passing fancy.

But of this, of my love for you, I am more certain than I have ever been of anything.

This is not something I will grow out of. This is not something that will fade. This is something I will carry with me for the rest of my life, whether I want to or not.

And I will keep it locked away, because I would rather love you in silence than lose you forever.

So I’ll fold this letter, tuck it away, and pretend it doesn’t exist.

Because you will never know.

—Yours (though you’ll never know it),

You signed your name, sniffing as you pressed your palm against the parchment, as if you could smooth away the trembling emotions trapped in ink.

There. It’s done.

It had felt good, in a way, to let it all out. But just as you predicted, writing it down hadn’t changed anything. Hadn’t lessened the ache or made your heart any lighter. If anything, it felt heavier, the weight of your unspoken love solidified in every word scrawled across the page.

You exhaled, folding the letter carefully—almost reverently—before setting it on your bedside table. You had every intention of tucking it away in your trunk, hidden beneath layers of robes where no one would ever find it.

But exhaustion was already pressing at your bones, and you thought, I’ll do it in the morning.

So you blew out the candle, turned onto your side, and let sleep pull you under.

Sunlight streamed through the windows when you woke with a start, your stomach dropping at the realization that you’d overslept.

“Shit,” you mumbled, throwing the blankets off and scrambling to dress as your roommates bustled around, already halfway through their morning routines.

“You must’ve been exhausted,” one of them teased as you tugged your uniform into place.

You barely heard them, too busy cursing yourself for missing breakfast. By the time you grabbed your bag and rushed out of the dormitory, your mind was already occupied with the day ahead—assignments, Professor Ronen’s latest essay, and the Quidditch scrimmage planned for the afternoon.

You never even glanced at your bedside table.

Never noticed the missing letter.

Nevertheless, your day had passed by like any other.

You’d managed to dodge Sharp’s wrath over a half-finished potion, spent lunch laughing with Ominis over Sebastian’s latest disastrous attempt at sweet-talking Imelda into lending him her broom, and successfully avoided thinking too much about the letter that was supposed to be ash by now.

Everything was fine.

That was, until you walked into the Great Hall for dinner.

At first, everything seemed as it always was—the low hum of conversation, the clatter of cutlery against plates, the floating candles casting their soft golden glow over the long tables. Your stomach grumbled at the scent of roasted chicken and buttered bread, and you barely gave a thought to where you would sit as your gaze instinctively flicked to the Slytherin table.

And there he was.

Sebastian sat in his usual spot, right beside Ominis. You felt the familiar pull of his presence, the way you always did, like some unconscious part of you sought him out before you even realized it.

But then, something shifted.

Sebastian wasn’t eating.

His hands were occupied—not with a goblet or a fork, but with a piece of parchment, one he had just begun to unfold. His brow furrowed slightly as his fingers smoothed out the creases, his dark eyes scanning the words in front of him.

You barely noticed the way your heart slammed against your ribs.

Because you knew that letter.

You knew that parchment.

You knew what he was reading.

Time slowed to a crawl, your breath halting as you stood frozen in the doorway, the warmth of the Great Hall vanishing, replaced by a creeping cold that wrapped around your spine and sank its claws deep into your chest.

Sebastian’s expression went slack.

His lips parted slightly, his brows drawing together in something unreadable as his eyes flicked over the words—your words—the ones you had never intended for anyone, let alone him, to see.

Ominis was speaking beside him, his mouth moving, probably teasing him about something, but Sebastian wasn’t responding. He wasn’t reacting, wasn’t moving. He was just reading.

Your stomach twisted violently, nausea rising in your throat as panic set in.

No, no, no, no, no.

Your breath hitched, your lungs seizing in panic as your mind raced— He hasn’t finished reading it yet. He can’t have. Maybe I can get to him, grab it before he—

But then his eyes lifted. And found yours. Everything inside you froze.

His face was unreadable, his dark gaze burning into yours with something too raw, too intense to decipher. And then—

Sebastian stood to his full height.

The parchment was still in his hands, crumpled slightly in his grip, like his fingers had tightened around it involuntarily. His mouth parted, as if he were about to say something—

And that was when your body made its decision.

Run.

You spun on your heel and bolted.

You heard the scrape of Sebastian’s chair against the stone floor, the sharp inhale of Ominis beside him, the sudden uptick in murmurs as people took notice. But you couldn’t focus on any of it—only the sheer, overwhelming need to get out, to get away, to put as much distance between you and that letter as humanly possible.

Your robes billowed behind you as you pushed past a group of Ravenclaws near the entrance, ignoring their startled protests. You didn’t even know where you were going—only that you had to move.

You barely made it into the corridor when you heard it.

“Oi!”

Sebastian’s voice, sharp and demanding, echoed off the stone walls.

You risked a glance over your shoulder and immediately regretted it.

He was right behind you, his expression set in something fierce—determined. His grip was still tight around the parchment, his knuckles white, and oh, Merlin, he was gaining on you.

You whirled down a side hall, nearly colliding with a suit of armor as you ducked around a corner. The adrenaline was making your limbs feel weightless, your body moving on pure instinct. You knew—knew—that running made you look guiltier, made it clear beyond a doubt that the letter was yours, but Sebastian knew your handwriting.

There was no talking your way out of this.

So you ran.

And he followed.

“Bloody hell, will you stop running?”

No. Absolutely not.

Your heart threatened to claw its way up your throat as you rounded another corner, nearly losing your footing in your panic. You had no plan, no destination—only the singular, desperate urge to get away.

But Hogwarts was only so big.

And Sebastian Sallow was faster than you.

So you did the only thing you could think to do—you ran for the nearest exit.

The heavy wooden doors of the castle loomed ahead, and you threw yourself at them, bursting into the crisp evening air.

The temperature was cooler out here, the autumn wind biting at your skin, but you barely noticed. The sky was deep blue, streaked with the last remnants of sunset, the grounds bathed in the soft glow of torchlight.

And still, you ran.

The wide expanse of the courtyard gave you space—space to sprint, to put real distance between you and the boy who held your heart in his hands, ink-stained and utterly exposed.

But then—

“Oh, for Merlin’s sake—”

A heavy force collided into you from behind, and suddenly, the ground was no longer beneath your feet.

A startled gasp left your lips as the world tilted, and then—

You hit the grass, hard.

The weight of another body pressed down on you, solid and warm, pinning you beneath them.

For a moment, everything stilled.

The only sounds were your own ragged breaths, your pulse roaring in your ears, and the undeniable, shuddering exhale from the boy who had just tackled you to the ground.

Sebastian.

You felt him shift above you, his hands braced on either side of your head, his chest rising and falling as he caught his breath.

The letter was still clutched in his fist, crumpled and worn from the chase.

And then—

“Are you absolutely mental?” His voice was breathless, frustrated—wild.

You flinched, panic curling up your spine, your body trembling beneath him.

“Sebastian,” you gasped, trying to squirm away, but he wasn’t having it.

“No.” His tone shook, his grip tightening on the ground beside you. “No, we’re going to talk about this.”

Your heart lurched. No, no, no, this wasn’t happening.

You squeezed your eyes shut, every fiber of your being screaming at you to run again, to somehow undo all of this.

But you were trapped.

Not just by his weight—not just by the way his arms and legs bracketed yours, caging you in—but by the look on his face.

His eyes.

Dark and intense, searching yours like he was trying to find an answer you hadn’t given him yet.

You swallowed, chest rising and falling too quickly, your hands curling into the grass beneath you as you tried to breathe.

Sebastian’s grip on the parchment tightened. “This—” his voice was lower now, unreadable, “—this isn’t a joke, is it?”

You swallowed, trying to force words up your throat. Your lips parted.

“I—” Your voice cracked. “I didn’t—”

“Because if it is,” he continued, his gaze darkening, intensifying, “it’s a cruel one.”

Your breath hitched, your body locking up beneath him.

A cruel joke?

"W-what?" you breathed,

Sebastian's grip on the letter was so tight now that the parchment crinkled loudly between his fingers. His other hand was still braced beside your head, his body caging you in, radiating heat, tension—something dangerous.

"You heard me," he said, his voice rough, barely controlled. "Is this a joke? Some sort of—of—prank?"

The very thought made your stomach twist. How could he—how could he even think—

"Of course not!" The words came out more forcefully than you intended, your panic spiking.

His jaw clenched. "Then why the fuck did you run?"

"Because!" You spluttered, incredulous. "You-you were- how the hell did you even get that?!"

Sebastian let out a sharp laugh, shaking the crumpled parchment between his fingers. “How did I get it? Oh, I don’t know, maybe because it was sent in the mail?!” His gaze burned into yours. “And it had my bloody name on it?!

"But I never sent it! I—" The words caught in your throat, a frantic, garbled mess of emotion and panic. You couldn't even think straight, not with him right there, not with his weight pressing you down, his breath still ragged from chasing you.

Sebastian scoffed, shaking his head in disbelief. "Oh, so it just magically appeared in the post? Someone sent it, and seeing as it’s your handwriting, your words—your fucking confession—I’d say that narrows down the list of suspects."

Your mouth opened and closed, but your brain refused to supply a logical defense.

You had left it out.

And your roommates—oh Merlin, they must have seen it, assumed you had forgotten to send it, and done you the favor of making sure it got delivered.

Your breath shuddered as the weight of it all crashed over you, the full, awful realization that everything was ruined.

Tears burned behind your eyes, hot and humiliating, and before you could stop them, they spilled over, sliding down your temples into the grass beneath you.

“I’m sorry,” you choked out, voice thick and uneven. “I—I never meant for you to see it. I was going to burn it, I swear—”

Sebastian’s entire body jerked like you’d just hexed him.

His anger—sharp and scorching only moments ago—immediately cracked, giving way to something horrified, something panicked.

“Oh—fuck,” he breathed, his grip on the parchment loosening as his weight shifted. “Shit, no—don’t—”

And then, in a blur of movement, he was off you, scrambling backward like he’d just been hit with a Stunning Spell.

You sucked in a breath at the sudden loss of warmth, blinking up at him through wet lashes as he kneeled beside you, hands lifting slightly like he wanted to reach for you but didn’t know how.

“I’m not mad at you,” he rushed out, voice hoarse, urgent. “I swear, I’m not—I just—fuck, I didn’t mean to—”

You buried your face in your hands, curling in on yourself as the shame closed in.

“No, it’s my fault,” you rasped, words strangled and raw. “I should have just—kept my feelings to myself. I should have never written it down, I don’t know why I—”

"Hey, hey—" His voice was softer now, no longer demanding, no longer frantic. A warm hand hovered near your shoulder, hesitant, but you were already spiraling.

"I—Merlin, why did I even listen to Witch Weekly?" You let out a miserable, watery laugh, rubbing furiously at your face as you tried—and failed—to control the mess of emotion in your chest.

Sebastian made a noise, almost like a pained laugh, but his eyes were still frantic, still burning with something raw and unsteady.

“So... it’s true?” His voice was quieter now, rough, but no less intense. “What you wrote?”

His fingers finally touched your wrist—not enough to pull your hands away, but enough that you felt it. Enough that it sent a ripple of awareness through you.

“Tell me,” he murmured, and you could hear the strain in his voice now.

Slowly, painfully, you lowered your hands from your face.

Sebastian’s gaze burned into you, desperate and unreadable.

Your throat was tight, your breath uneven.

But you couldn’t lie.

So you nodded.

A sharp exhale left him, his hand dropping from your wrist to clench in the grass beside him. His head tilted back slightly, his jaw tight, his Adam’s apple bobbing as he swallowed hard.

"Fuck," he muttered under his breath, running a hand through his hair again.

You winced. "I know," you whispered, curling your arms around yourself. "I know. I'm sorry. You can just—just forget about it, okay? I know it's probably weird, and you don't feel the same, and I just—I'll move on, alright? I can—I can pretend this never happened, if that's what you want—"

Sebastian let out a sharp, disbelieving laugh.

And then he lunged for you,

Before you could even react, he was on you again, wrapping his arms around you and pulling you into him. The force of it knocked the breath from your lungs, your hands flying up to brace against his chest as he rolled, flipping the both of you over until you were the one on top, sprawled against the solid warmth of his body.

A startled noise left your lips as he crushed you into his chest, his arms locking around you like a vice. His heartbeat pounded beneath your cheek, wild and erratic, his breathing uneven.

"You're such an idiot," he muttered into your hair, his voice rough, still shaking with disbelief.

Your brain was struggling to keep up.

"W-what—?"

"You think I don’t feel the same?" He let out a breathless, almost hysterical laugh, tightening his hold around you. "Merlin, do you even hear yourself?"

Your stomach flipped, something warm and dangerous flooding your veins.

Sebastian's grip didn’t loosen. If anything, it tightened, his hand splaying wide against the small of your back, pressing you even closer to him.

"You’re not moving on," he said fiercely. "You’re mine."

Your breath hitched. "Wh-what?"

Sebastian groaned, his head dropping back against the grass, his fingers flexing against you like he was barely holding himself together. "Fuck, do you even know what you've done to me?"

You swallowed hard, your fingers still curled in his robes, every inch of you hyper-aware of just how close you were.

"I—"

"You've wrecked me," he muttered, almost like an accusation. "I thought—I thought I was losing my mind. You had to know, you had to have noticed—"

"Noticed what?" you whispered, your voice barely there.

Sebastian let out a shaky breath, and then his hands slid up your back, one curling around the base of your skull, the other gripping your waist, firm.

"Noticed how fucking obsessed I am with you."

Your body locked up.

He flipped you again, faster this time, pressing you down into the grass beneath him, his weight heavy over yours. His breath was ragged, his expression wild, his eyes—

His eyes.

Dark, burning, hungry.

"I love you," he murmured, his voice almost pleading, like he needed you to hear it, to understand. "I’ve loved you for so fucking long."

"You—" The words tangled in your throat, your hands fisting in the fabric of his robes. "You don't have to say that just because you—because you feel bad—"

A sharp sound left his throat—something between a laugh and a growl, something raw and frustrated.

"Are you serious right now?" His grip on your waist tightened, his fingers pressing into your skin through the fabric of your robes. "You think I’m saying this out of pity?"

You flinched, shaking your head quickly. "I just—I don’t understand—"

"Fuck," he muttered under his breath, dropping his forehead to yours for a fleeting second, like he needed the contact just to ground himself. "You really don’t know, do you?"

Your breath was uneven, your mind spinning. "Know what?"

Sebastian exhaled sharply, and then—

He kissed you.

It wasn’t soft. It wasn’t hesitant. It was a claim.

His mouth crashed against yours, desperate, consuming, like he’d been starving for this.

A shocked noise slipped from you, but he swallowed it, pressing closer, deeper, one hand sliding into your hair while the other anchored itself at your waist.

Heat flooded through you, overwhelming and intoxicating, sending shivers down your spine.

You had imagined this before—god, you had imagined this in the dark, alone, staring at your canopy and aching for him—but nothing could have prepared you for the way he felt.

The way he took. The way he gave.

You barely had time to catch your breath before he tilted your head back and kissed you again—harder, deeper, like he was trying to ruin you.

Like he needed you as badly as you needed him.

"Still think I'm lying?" he murmured against your lips, his voice a rough, wicked thing.

You shook your head, dazed, your fingers curling into his robes as you pulled him closer, your answer slipping out between gasps.

"N-no."

Sebastian smirked against your mouth, his grip tightening.

"Good," he breathed. "Because I'm never letting you go."