It happens three days into the school year. It has been a perfectly normal day until night time comes. His breathing is laboured, oxygen scorching his lungs, as sweat-soaked sheets cling to his clammy skin. He thinks he can smell blood and something floral before he awakens.

His roommates are up instantly, rushing out of Ravenclaw Tower and trying to find their Head of House. He's screaming but trying in vain to get to his feet. Every atom in his body is pushing him to sate the ache now deep in his blood and bones. It feels like he will die if he can't get to-

His roommates push him to the floor, shouting at him to stop. He fights and the growls that escape him are more animal than human. He bites his own tongue and blood drips down his chin. He can't stop though because-

He can feel her in every space between muscle and marrow. She is screaming too. And she doesn't understand, can't grasp what is happening because she is his now and he is hers. And he aches for her, he is burning for her, bleeding for her, and she-

She screams all the way from Gryffindor Tower.

Rosie, he says through a mouthful of blood, Rosie.

She is only fourteen and barely out of childhood. He's sixteen and becoming more man than boy. She is so very young with a still blossoming body with freckles and messy red curls. He's so tall now that he hovers over her and she has to nearly tilt her head all the way back to look into his blue eyes.

She looks scared and unsure. Her doe eyes are large and hypnotic and every cell in his body just wants to touch the slope of her slender neck, wants to kiss the constellation of freckles on her collarbone, and wants nothing but-

"I've never even had a boyfriend," She tells him, her hands clenching her school skirt. "And you've…"

He inclines his head, watching her fumble over her words. Out of all the cousins, she's never been the most composed one (that's Victoire) nor the best with words (that's Roxanne) but Rosie is smart and determined and she learns faster than all her classmates. Watching her try to find the right words for their situation (well, there weren't really any) is almost painful.

"I've had two girlfriends," He answers her unsaid question. "Three, if you count the girl in France last summer."

She blushes and it isn't pretty. It makes her freckles stand out more and it clashes with her hair. He doesn't really understand this thing inside him and why he doesn't think everything she does is amazing. Yet, he thinks it should make him want to worship her.

It doesn't. He can just feel a longing underneath his skin. His fingertips almost tingle with little shocks and he wants to reach out and curl his arm around her waist. He wants her closer and breathe in her floral scent.

"I…" She lets out a sigh. "I don't know how this is supposed to work."

He shrugs. "Me either."

She bites her lip and looks frustrated. "Well, what do you know?"

He wants to smile because there is the fiery girl who backs down to no one. There is the girl who fights with James because he is being an entitled brat and who tells Molly to shove it up her arse when she keeps spouting about some nonsense. This is the Rosie he likes, demanding and no bullshit.

"Practically nothing," He confesses with a frown.

She lets out another sigh.

His fingertips tingle.

His mother sends a long letter, detailing as much as she can about his situation but she doesn't really understand it either. Because she's chosen the man she is with. She isn't weighed down by some biological response, dictating who he should procreate with. He's had less of the Veela in him and yet-

Yet he is practically breaking down from the fucked up cocktail of emotions and hormones overtaking him nearly every minute of his waking existence. He can't grasp the existence of such a curse. How magic can be so vicious and unkind and why-

Why her?

Out of the billions of women in their corner of the universe, why her? Why it has to be his younger and naive cousin who is uncomfortable with even the thought of holding a boy's hand? Why would his blood pick someone he would've never looked at twice?

He pens a polite response to his mother and keeps his resentment to himself.

He hasn't lied to Rosie. He's only had two or three girlfriends but he's snogged a girl in a corner every once in a while when the mood struck him. Before all of this, he thinks he'd only taken two things from his Veela ancestry – his looks and charm – and on occasion, a wanting in his system he attributes to being a teenage boy. Yet having Jessica Abbott in his arms does nothing for him – nothing at all.

No excitement thrums in him except a nearly constant disinterest. He is furious and unsettled and he rushes off to write another letter for someone who could finally give him answers.

His great-grandmother's letter arrives the next day. It's long and entirely in French and he reads the entire thing from top to bottom, twice. He is shaking and miserable at the end of it and he is quick to pen a reply. It is short and to the point.

You're wrong.

Because she has to be. He cannot live with the truth she has given to him. He cannot live in a world where his fate is sealed. He cannot accept the idea of being one half of a whole when he is content to never be complete.

Christmas at the Burrow comes and he sits amongst the madness of his relatives. It's loud and obnoxious chaos that makes him want to sulk in a corner with a bottle of really strong eggnog and wish for oblivion. Unfortunately, Grandma Molly is having none of it as everybody has to enjoy the Weasley Christmas spirit or have your special Christmas wool sweater revoked. He can pretty much live without said sweater but his parents are giving him looks and even Dominique stops fawning over her boyfriend, Frankie Longbottom, long enough to pinch him in the side.

"Don't be a grouch," She mutters to him.

He scowls at her and salutes her with the finger before rushing upstairs for some peace and quiet. He ends up in his dad's old room and he eyes the now practically bare room before taking a seat on the old, decrepit mattress. It's heated in the room despite it being wintertime but the Burrow had always been warm and he sighs as he looks at the stars from the opened window. It seems almost surreal.

Last year he'd been down there without a care in the world, just having lost his virginity to Veronica Nott and everything was good. He was happy. He was free. And now-

"Louis?"

He keeps himself still even as all his senses are attuned to the figure in the doorway. He could feel her presence like static in the air. The oxygen he breathes in feels charged with power as she enters the room. The aging floorboards make the barest of creaks beneath her light footfalls.

"Rosie,"

He finally turns to look at her and has to hold his breath. His heart is quickening, thumping in his chest so fast that the air goes to his head, he feels almost nauseous. His hands are shaking and he clenches them, determined to keep control. He wants to run away from the sight of her in that holly green dress and find a place that feels like himself again.

Her hair is more tamed tonight in pretty red curls and that damn green dress looks so lovely on her, he wants to puke. The freckles on her collarbone are like flecks of cinnamon on milk. Her doe eyes are wide and concerned and her teeth are biting into her small mouth. He is going mad.

"Rosie," He gets to his feet and she startles, leaning towards him unconsciously. "I have to go."

"Go where?"

"Away."

"From me?" The steel underneath her shows itself. "Like you've been doing for months?"

He has nothing to say that because he has gone out of his way to keep away from her. The curse in his blood has been ruthless as a result and he spends nights retching blood in the loo. It has no intention of killing him but it would punish him. For denying this is a sin and he would rather go to hell than give in.

She softens, his silence weighing on her, and he can see the vulnerability in her doe eyes. So fucking young and naïve and-

"Louis?" She reaches for him with a shaky, unsure hand. "Please, why do you-"

"No!" He pushes her away, practically running to get away from her. "I can't do this!"

"Louis!"

He runs with unsteady knees.

"This is going to kill you," Victoire is leaning on the doorway of the loo as he wipes his mouth with the back of his hand, the red on his skin is vibrant. "You can't keep fighting it."

"Watch me," He manages to get out before he is choking again, blood runs down his chin to stain the light blue cotton of his shirt.

He grimaces and gets to his feet to wash in the sink.

"Why do you fight it?" His sister continues to pester him.

"Because I didn't want this," He splashes cold water on his face and watches the swivels of pink go down the drain. "I never had a choice in any of this."

"So, just because you had no say in who your biology deems as your mate, you act like a child about it?" Victoire stares at him in disdain. "Grow up, Louis."

He turns around to glare at her, anger thrumming in his bloodstream like acid. "How would you understand? You got to pick who you're with!"

"Yes," She keeps a hand on the slight swell of her tummy. "I did get to pick Teddy. I got to pick my life. But this is your destiny-"

"Really?" He scoffs. "You and mémère with your notions of fate and soul mates, like this is some grand romantic tale."

Victoire's blue eyes are narrowed as he continues, "You all act like this is some beautiful gift. Like making me want to fuck our cousin is normal, sane. It's not."

"No," Victoire says. "But neither is destroying yourself to make a point."

Valentine's Day comes near like a loose manticore causing panic and mayhem wherever it went. He spends breakfast ignoring the rising pile of singing valentines beside his plate and eats his eggs benedict like nothing's the matter. Tristan Boot and Elliot Goldstein take the valentines from him and laugh obnoxiously at each one and he can care less.

"Oi," He nicks one of the louder valentines from Tristan and throws it into Elliot's porridge. "It's too early for this."

"Come on, pretty boy," Elliot replies. "You're the only one who gets this treatment every year. At least, let us live vicariously through you."

"You're pathetic, Goldstein."

He shakes his head at his friend before he has the sudden urge to look at the Gryffindor table. Rosie is looking astonished down at the valentine's card in her hands, it's made of expensive embossed pink paper and it smells of roses. She's reading whatever's on it before looking up at him with her confused doe eyes. She glances from him to the letter before she wordlessly tucks it into her Potions textbook.

He can't help himself from bristling and he grips his fork tighter.

He closes his eyes and tries to regain control but the beast inside him is ravenous and his chains are weakening.

Scorpius Malfoy is lanky and practically colourless but he's already the same height as Louis and can look the older boy dead on in the eyes.

"How'd you know it was me?" The Slytherin boy asks casually like they're friends discussing Quidditch and it makes him want to bruise his aristocratic skin.

"I could smell your cologne on that damn Valentine," He gets out between his teeth.

Underneath the scent of roses was the posh cologne Malfoy uses and he wants to both set parchment and sender on fire.

"Rosie seemed to like the valentine," Malfoy tells him.

And he clenches his teeth. "You don't get to call her that."

"What? Rosie?"

His shoulders hunch and Malfoy's survival instincts seem to remember themselves and he stops trying to antagonise the older boy.

"Alright, I get it," The Slytherin raises his hands in surrender. "She's yours or some tosh like that."

Louis keeps glaring at him.

"But what I don't get though," Malfoy cocks his head to the side. "Is why you don't seem to be hers? What's up with that?"

"'Sup, Lou?" James plops down beside him at his table in the library. "Getting all ready for NEWTs?"

Louis goes back to his reading. "As a matter of fact…"

"Good, 'cause OWLs are coming up for me and I was hoping being the awesome cousin that you are that you could help me out with that." James smiles that easy, disarming smile that seems to work on girls for some reason. "Unless, you're still doing that tortured pining over Rose because-"

"James, I am going to disembowel you if you don't stop talking right now."

Louis is surprised by the silence that follows. James never shuts up. It's his thing along with messy, windswept hair and an uncanny ability to know which girls use charms to make their chests look bigger.

He looks up to find James, smiling and disturbingly quiet.

He narrows his eyes at the Gryffindor before James grabs his quill and parchment and starts writing in large letters over his detailed notes. Oh for Merlin's sake-

LOUIS LOVES ROSIE

"James-"

But his cousin is already out of his seat and away from where his fists can pummel him. James gives him a salute and a cheeky grin before running off like some demented spirit.

Louis hates his family.

Louis spends the rest of the month trying to avoid his relatives who seem determined to bother him about Rosie and his 'Grouchy McGrinch-y Pants' behaviour (Lucy's wording). Molly corners him in their common room one night and basically tells him to stop being a prat. Roxanne writes a very eloquent and very long essay on why he should stop denying his feelings for Rosie already. Freddie sends him a glitter bomb that exclaims, 'CONFESS, YOU DOLT!'

And even young, sweet Lily gives him a box of sugar quills for Rosie.

The madness never ends and he is at his wit's end with the unnecessary meddling of his cousins. As if his own immediate family isn't giving him enough grief with their worried letters (most of which detail how happy he would be if he just gives in). His mum is cloying, his sisters are bitchy and his mémère sends him the bitterest dark chocolate from France.

He stops as he finds Albus sitting outside the entrance of his common room. Not him too-

"She's miserable, you know," The middle child Potter gets to his feet, dusting off his green Slytherin robes. "She doesn't talk about it but…she's sad, hurt about all this."

Louis keeps quiet as Albus dresses him down with his green eyes and an accusatory tone.

"She doesn't get what's wrong with her, what you think is wrong with her," The younger male bites out. "Like she's deficient somehow because you seem to want to do everything but accept the fact that she's it for you."

Louis scowls and tries to swallow the blood threatening to choke him again. He would not be broken in by some practical boy-child. "I want her to be happy. I want to set her free."

"But there is no freedom, Louis, is there?" Albus' smile is painful and almost mocking. "There's just this…purgatory for you and her, right?"

"No," Louis exhales. "It's Hell."

Hugo has been mostly silent throughout the entire thing. Rosie's younger brother alternates from looking confused and just downright upset.

Louis chooses to ignore him until one day as he's walking down the hallway to his Charms class he encounters Hugo who proceeds in punching him in the mouth.

"Prick!" The younger boy snarls. "You don't deserve her!"

He touches the blood at his mouth and silently agrees.

It finally comes, the moment when he can no longer run. He is shaking and pale, having lost more blood than is probably healthy and he can only watch, nauseous, as Rosie screams at him.

"Am I that horrible?" She shoves at him, hard, fuelled by anger. "Am I that unworthy of you that you treat me like rubbish?"

He can't say anything, he can't do anything as she unleashes her fury. All these months of him running and pretending like Rose Weasley doesn't exist has made him weak and yearning. Her very nearness to him right now is like a balm for a festering wound. She is the only thing that matters.

"Louis!" She shouts. "What is wrong with you?"

"You," He answers her, breaking. "You are what's wrong with me."

She growls and slaps him and he steps back more from shock than force.

"I didn't choose you!" She cries. "I didn't fucking choose you either!"

And he feels like he's choking on his blood again, everything burns and aches and he is so tired. He just wants to feel better. He can't stand this wretchedness anymore. He's not strong enough to keep on fighting.

"I'm sorry," He captures her wrists as she moves to strike him again, keeping her still even as she struggles. "I'm sorry!"

"Shut up!" She gasps out as he pulls her closer and holds her. "Stop!"

"I'm sorry," He murmurs in her messy hair. She smells like flowers. "I'm so sorry, Rosie."

Rosie doesn't trust him and it's understandable. She looks at him with doubt in her eyes and he lets her. He deserves it, more than anything. Yet he still walks her to her class each morning, sits beside her at the Gryffindor table during lunchtime, and he buys her sugar quills from Honeydukes. These are simple things but-

One Hogsmeade weekend, they're at the Three Broomsticks at a table filled with their cousins. Rosie is in between Molly and Lucy and he's across from her, watching her fiddle with her warming bottle of Butterbeer and asks her, "You want another one?"

She looks up at him with those doe eyes and nods. He smiles at her before getting up.

-she lets him stay and that's all that matters.

Rosie spends her fifteenth birthday on the last day of the school year and they celebrate at the Astronomy Tower with a bottle of Firewhiskey with her favourite macaroons.

She doesn't drink normally and is already quite tipsy from a few sips and he listens to her hum as she bites into a red macaroon.

"You know, Louis," She tells him. "I've decided to become a pastry chef."

He's lying comfortably on the nest of sheets and cushions they'd stolen from their common rooms and he opens an eye to see her smiling lovingly at a pink macaroon. "And why is that?"

"So I can have as many macaroons as I like," She licked cream off her lips. "Free macaroons for life."

"Okay," He smiles at her fully, amused by her antics. "Can you bake?"

She shakes her head. "Not a bit."

He wants to laugh but she hands him a purple macaroon and scoots closer to him to use him as a pillow and he can't really think very well anymore.

"I almost burned the house down when I tried to bake cookies," She explains to him. "My mum banned me from the kitchen for half a year for it."

"But how can you be a pastry chef, then?"

"It's just a dream, I guess." She shrugs. "We all need one impossible dream."

He chuckles. "And yours is to become a pastry chef."

"Yes," She turns to him. "What's yours?"

He spends summer with Rosie at his great grandmother's house in Southern France. Rosie makes him bring all his Fifth-year books and study modules with them so she can start studying for her OWLs. He keeps a stash of chocolate cigs and whiskey in their room and watches Amelie when he gets bored. She lounges about in his old Quidditch jerseys and eats truffles in between memorizations.

His mémère thinks Rosie is pretty and smart while his pépère lends him his car so they can drive around the countryside during afternoons with perfect weather. Rosie makes him drive them to Paris one day to wait in line forever to go into the Louvre and drink thick, hot chocolate in cafes. He buys books on Philosophy and more whiskey. Rosie reads mythology and draws charcoal sketches of birds.

It's almost idyllic and he can never remember feeling this content. He can't remember to hate himself for it.

They drive to Italy one day and bump into the Scamander twins. Rosie is friends with Lorcan and she greets him with an enthusiastic hug. Louis keeps quiet during their dinner as Lorcan regales Rosie with tales of their adventures in the Amazon. Lysander gives a word here and there but mostly stares at Louis questioningly over his cup of red wine.

Louis decides he needs air and he goes to the balcony to try and clear his head. It's cold and he shivers underneath his thin jumper. Lysander joins him and takes out a clove cig from his pocket.

"Want one?" The sandy blond asked.

Louis said yes and they smoked as the sun went down.

"Your brother, does he…" He finally tries to summon the courage to ask because he thinks he will very much go mad or commit an act of violence if he doesn't. "Does he have feelings for her?"

"Nah, wrong Weasley girl," Lysander chuckles. "He likes Lucy."

"Oh," He blinks before looking back at him again. "And you?"

Lysander smiles like he's an idiot. "I'm gay."

"I think Lysander fancies you." Rosie whispers in his ear.

He rolls his eyes and pulls her closer, burying his face in her hair and ensuring a mouthful of red curls for him the morning. "Shut up."

"But I really think he-"

He tickles her until she's out breath.

She's panting underneath him and he stares into her dark eyes and wants to drown in them so he holds his breath and kisses her. The burning in his lungs and the softness of her lips are a deadly combination and he ends the kiss to her giggling.

"But if you had to pick a bloke…"

He's in the shower, the hot water almost blissful against his chilled skin, when he feels the lightning in the air as Rosie is behind him, pressing herself against his back. She's naked and her small breasts are slick against his skin. He holds his breath and tries to count the tiles in front of him but it's no use. His mind is weightless and gone.

"Louis," Rosie murmurs against the droplets of water on his back. "Why haven't you touched me?"

He inhales. "You're still young…"

She places a kiss between his shoulder blades. "I'm not that young."

Exhales.

"Louis?"

He turns around in her embrace, looks into her doe eyes and lovely, perfect face before dropping to his knees, nudging her legs apart and tasting her.

She moans.

And it's amazing.

Rosie's hand is on his cock and she's placing playful little pecks all over his face, anywhere but his lips and he growls before he pushes her more firmly against the windowsill of their room and kisses her properly. She laughs when he sucks on her tongue and moves her hand faster. He groans and shudders.

And she is perfect.

She is giddy when she gets her Prefect's badge and they celebrate with a bottle of tequila Teddy sends as a gift and his mouth on her breasts as he shoves fingers into her wetness. She returns the favour with her mouth around his cock when he gets his Head Boy badge.

Life is good.

Summer ends and they're back at school. He enters the prefect's compartment with Rosie who takes a seat with the other Fifth-year prefects. Veronica Nott gives him a smirk and he pretends not to see it.

Rosie doesn't.

They don't fully have sex till his seventeenth birthday. It's November and he's eating the homemade chocolate cake from Victoire and Rosie is laughing at the hideous scarf Dominique sends as a gag gift. They're at the Astronomy Tower and its way past curfew but neither of them really care. They finish opening all his presents and Rosie makes a list of people to owl thank you notes to. Then she plops down beside him on the blue and red nest of cushions.

"I belong to you, don't I?" She asks.

He tucks her hair behind her ear then leans closer to kiss the sensitive lobe. "Yes."

"And you belong to me?"

"Yes," He kisses down her cheek, to her neck where he bites into the cluster of small freckles there. "All yours, Rosie."

"Prove it to me." She moves to kiss him hotly. "I want you so much."

He must be dreaming, he thinks. Surely dreaming, as Rosie takes his hand and slides it underneath her school skirt.

She's wet and he can barely control himself. The starved monster inside him has been denied for too long, fed scraps of Rosie's magnificence and now that it is offered its pay in full, it wants all.

He pushes Rosie down the mound of cushions and undresses her, worshipping her skin, freckles all over, like stars in the universe that is her body. He kisses her between her legs and tastes her come in his mouth before he presses himself inside her and she-

She feels-

She is-

"Bloody hell," He breathes out into her neck. "You feel incredible."

"We haven't even started yet." She tells him with a chuckle.

He smirks at her and begins to move.

And-

"Oh, Louis…"

Yes, darling. My darling.

He is ravenous for her. Every part of him seeks her out, the taste of her lips, the feel of her skin. She is macaroons and Firewhiskey, truffles and whiskey, tequila and come. She is everything. Any why did he ever deny himself of this?

He must've been mad, he thinks as he has Rosie in his lap. She is biting his shoulder as they move together, trying to muffle her moans so his roommates can't hear her. He's cast a Silencing charm but his Rosie worries too much. And she is a good girl and if they catch her like this-

Debauched, moaning, sweaty, wet…

Messy, so messy…

And oh Merlin, so hot…

She is…

She climaxes with a cry of his name.

-they would die from jealousy.

"Why did you keep running away all those months ago?" She asks, her fingers tracing the skin of his chest, the bumps of muscles and the dips between his bones. "Why did you want to keep us apart?"

"I was…angry and scared," He tries his best to give a good and honest answer. "I didn't want my life to be ruled by fate or destiny or some rot like that. I wanted to have a choice, to have my own free will over a gene that shouldn't have even been active."

She sits up and he follows her, the almost hurt look in her eyes alarming him to the fragility of this moment. "Do you regret giving in then? Do you regret being with me?"

"Not you. I could never regret you." He traces her bottom lip with his thumb. "You're all I need."

She keeps pushing. "But do you regret not having a choice?"

"Yes."

She stills and then she shutters like a closed door, she moves to get up but he pulls her back, into the warmth of his arms, her back pressed to his chest. "Louis, let go of me."

"Let me finish."

She stops struggling.

"I do regret not having a choice about this whole thing," He kisses her nape when she begins to tremble. "But if we had been given a choice, we would not be together."

Her voice is small. "Why not?"

"Because we're cousins, Rosie," He laughs into her neck. "Grandma Molly and Grandpa Arthur are still reeling from all this, if you can remember?"

She blushes and relaxes into his arms. "Scorpius says that Purebloods used to marry their cousins all the time."

He caresses her midriff and hums.

"You should stop taking advice from Malfoy, Rosie."

Rosie rolls her eyes. "You just hate him because he's blonder than you."

He scoffs. "Yep, that's why."

"I love you."

"I love you too."

"Well, duh."

"Shut up."

Sometimes he maps out the worlds hidden inside her body, the countries written on her skin and he tries to find his name. He thinks it's written in the spaces between her blood and bones. He thinks he can hear the echo of his name in the timbre of her voice. He thinks maybe he's always had a choice and he would've chosen the same ending anyway.

Because it's always been….

Rosie, he whispers her name, Rosie.

Notes:

Inspired by provocative envy's Dramione fic, Disasterology.