You Were Always Mine (Never His Sister #1)

Kai

She moves through this house like a ghost only I can see—bare feet whispering against the hardwood, hair spilling down her back in waves that catch the light and blind me until there’s nothing left but her.

Scarlett Everly. My step-sister. My sin.

She doesn’t know what she does to me when she laughs in the kitchen, when she hums under her breath in the shower down the hall, when she leaves her door cracked just enough for me to imagine things I shouldn’t be imagining.

She thinks I don’t notice. She thinks I’m normal—but I’ve never been normal—and the way she looks at me with those wide, startled eyes makes it worse, makes me want to cage her, corrupt her, and turn her into the thing I already see when I close my eyes.

The first rule when our parents married was simple: she’s off-limits. Don’t touch her. Don’t want her. Don’t ruin her.

I broke that rule the moment I saw her.

Scarlett walks past me now, head down, clutching her books to her chest like a shield, and I want to rip them away just to see her hands empty—just to see if she’d put them on me instead. I want to say her name out loud, taste it, drag it across my tongue until it burns.

But I don’t.

I just watch.

I always watch.

This is how it starts: the silence, the stolen glances, the ache in my chest that feels like punishment from a God I stopped believing in the night I realised I wanted my little sister.

And Scarlett?

She has no idea she’s already mine.

Her door closes, and I stand there in the hallway like some kind of lunatic—palms flexing at my sides, chest tight—because all I want is to push it back open and step inside.

I want to see the way she perches on the edge of her bed with her knees drawn up, how she bites her lip when she’s nervous, how she tucks her hair behind her ear when she thinks no one’s watching.

I want to ruin every little innocent habit until she can’t do them without thinking of me.

Scarlett doesn’t get it—she’ll never get it—that she lives in my head like a prayer turned dirty, a hymn twisted into something blasphemous, a sin I can’t stop worshipping no matter how many times I tell myself to stop.

I lean against the wall and close my eyes, listening to the soft scrape of drawers opening, the muffled thump of her footsteps, the creak of the mattress when she finally sits down.

Every sound is a tease, every reminder that she’s inches away—one thin piece of wood separating her from me—and it makes my hands curl into fists because I don’t trust myself not to break it.

The first time I thought about her like this, I swore it was just a slip, some fucked-up impulse I could shake off if I tried hard enough.

But it’s not gone. It’s worse. It’s in the way I can’t look at anyone else—the way no other girl feels real in my hands because they’re not her.

They don’t laugh like she does, don’t flinch like she does, don’t burn like she does when I get too close and she can’t pretend she doesn’t feel it.

Maybe she hates me for it. Maybe she wishes I’d disappear. But she hasn’t told anyone. She hasn’t run. She hasn’t locked that door—not once.

Which means part of her wants this, even if she won’t admit it.

I press my head back against the wall and let a smile cut across my mouth—sharp and wrong.

Scarlett can lie to herself all she wants.

But I know the truth.

She’s already mine.

Scarlett isn’t soft. That’s what kills me most about her.

She doesn’t glow like some fragile little angel; she burns—dark hair spilling like ink down her back, skin pale against it, lips too red for someone who pretends she doesn’t want to be seen.

Her eyes are the kind that cut straight through you, blue so sharp they look almost violent when she’s pissed—and God, I live for that look, the one she shoots me across the dinner table when my knee brushes hers under the wood.

She’s twenty, barely, but she carries herself like she’s older, like the world already broke her once and she dared it to try again.

Every move is deliberate—hips swaying when she doesn’t mean to, mouth curving into that wicked little half-smile she can’t hide, shoulders squared like she’s ready to fight me if I push too hard. And I will.

The door creaks open down the hall—not hers—and my father’s voice cuts through the silence.

“Kai? You’re still up?”

I drag my eyes off Scarlett’s closed door and force my tone flat. “Couldn’t sleep.”

He doesn’t press, just mutters something about an early meeting before disappearing again. His footsteps fade, the house settling back into quiet, and I almost laugh—because if he knew where my head was, if he knew what I wanted, he’d kill me with his bare hands.

Her door clicks then—soft, careful—and I straighten before I can stop myself. Scarlett steps into the hallway, hair loose around her shoulders, wearing a black tank top that clings to every sharp line of her body and shorts so small they may as well not exist. She freezes when she sees me.

“Kai.”

Her voice is flat, unimpressed—but her throat works when she swallows. “You’re lurking.”

I smirk, because she’s not wrong. “I live here. Not my fault you prowl the halls half-naked.”

Her eyes narrow, that dangerous blue slicing into me. “Don’t watch me.”

“As if I could stop.”

The words slip out before I can choke them back—low and certain—and for one perfect second she falters, lips parting like she doesn’t know what to say.

Then she scoffs, rolls her eyes, and brushes past me. Her shoulder grazes my arm—a deliberate little act of defiance—and the scent of her shampoo, dark berries and something floral, claws down my throat.

I watch her until she disappears into the bathroom and shuts the door, and I can’t help it—my mouth curves into that wrong smile again.

She can tell me not to look.

She can tell me not to want.

Scarlett doesn’t know what it means to be mine yet.

The bathroom light spills under the door, humming faintly, and I stand there too long like a freak until I catch myself and force my body back down the hall.

My room is supposed to feel safe, but it doesn’t—not when hers is so close.

I push the door half-shut, sit on the edge of my bed, and rake my hands through my hair until my scalp stings.

Five minutes later she comes out, steam curling around her, skin flushed from the heat, damp hair tangled down her back. She stops when she sees my door cracked and glares at me like she knows I’m watching again.

“You don’t sleep, do you?”

Her voice is soft but edged like glass.

“Not when you’re stomping around at midnight.”

Her brow arches. “Stomping? I was brushing my teeth.”

I smirk, leaning back on my hands. “Sounded louder from here.”

Scarlett shakes her head, muttering something under her breath as she passes. She doesn’t slam her door, though. She never slams it. She leaves it half-shut, just like always, and I feel the pull like a chain around my throat.

I should let it go. I should close my own door, bury my face in a pillow, pretend I’m normal—but instead I rise, pad down the hall, and knock lightly against her frame.

“Seriously?” she says, voice muffled but sharp.

I push the door open an inch, carefully, like I’m testing her. She’s perched on the bed cross-legged in those tiny shorts, scrolling on her phone, the blue glow lighting her cheekbones. She looks up and frowns.

“What do you want?”

I shrug, leaning against the doorframe like it’s casual. “Just making sure you don’t get scared of the dark.”

Scarlett snorts, shoving her hair back. “You’re the only scary thing in this house.”

The corner of my mouth twitches. “Good. Then you’ll keep your door locked.”

Her eyes narrow. “Why would I need to?”

Because I’d break it down if you did. I’d crawl inside just to hear the way you gasp when you realise you’re not safe with me.

I don’t say any of that.

Instead, I tilt my head. “You tell me.”

She rolls her eyes, muttering something about me being insufferable, and lies back on her bed, one arm thrown over her face.

“Goodnight, Kai.”

I should leave—that’s what she wants, what she expects—but I stand there a few seconds longer, watching the rise and fall of her chest, the bare skin of her legs catching the glow from the lamp, the sharp line of her collarbone.

When I finally pull the door closed, the image burns itself into me like a brand.