A/N: This is my first story in years. If you followed me for that Smash Bros fic I made 5 years ago, all I can say is: sorry man, maybe later.

If you had asked Eren yesterday to tell you how he saw Mikasa, he would have responded with one word: strong. He would see her soaring over the rooftops in ODM gear, dancing against the backdrop of the sky, silky black hair flowing in the wind as she effortlessly dispatched titan after titan. He would see her in their hand-to-hand combat drills, dropping sparring partners with precision-aimed punches and kicks. Maybe, if you really pressed him, he would recount to you with a blush the time he caught her coming out of a workout session in nothing but short shorts and a crop top, a sweaty sheen covering her lean body – a sight that had brought hot confusion bubbling up to the surface of his being.

Today, right now, the picture couldn't be more different. Before, it had seemed like he was always seeing her from the ground, be it trailing her in the Survey Corps or just knocked on his ass by a sparring partner.

Today, he's between her muscular legs, fucking her with all his energy.

To a soundtrack of wet slaps, grunts and whimpers he pounds away at her, Mikasa trembling with every thrust.

"~ahh – Ere-" her lover bends down to silence her cry with a sloppy kiss, plunging into her mouth with his tongue, invading her. She hums into him, tongues dueling for supremacy but neither quite winning for a few seconds until Eren has to break the kiss, longing to continue but lungs burning from his assault on both her holes. She's his, he needs to have her, to hold her, to own all of her, he needs it. He gives her another sloppy kiss before drawing back, just a little, so that their foreheads are touching, his green eyes staring deep into her onyx pools.

"Hey." His hands withdraw from her slim waist and travel up to cup her hotly blushing face, stopping only to squeeze her left breast for a second. "Do you know what this means?"

She shakes her head no, and he thrusts, deep, as if in punishment. She gasps and raises her head for another kiss, but he's just out of reach this time. Her eyes are glazed over, blinking, a little wet, deep, lustful. "It means you're mine." He traces a thumb, feather-light, across the scar across her left cheek. "You belong to me." He punctuates this statement by picking up the pace, just a little, his meat pushing in just a little bit faster.

For a second, he thinks he's gone too far – oh shit why did I do that, why, that's so corny and fucked up – that he's made a grave mistake. He didn't.

He first notices it coming, he swears, by her heartbeat. Maybe he's dreaming, too caught up in this ridiculous, too-crazy-to-be-true fantasy of fucking his badass adopted sister, but he swears, here, their chests, flush together, her breasts pillowing up underneath him, that he can feel it quicken. Then, her eyes – her beautiful, deep, dark eyes – widen a hair, and he's transfixed by the expression he sees there – a little bit of love, a little bit of fear, and enough heat to burn the whole city of Shiganshina to the ground. Then, her legs, he can't see them but god can he feel them, pull him in, and her pussy squeezes the life out of his cock, and she's coming undone around him, a soft, mewling cry escaping her lips and her body trembling in ecstacy.

He keeps jackhammering into her, through her trembling, her cries, her little moans and unladylike spasms. As Mikasa's orgasm winds down, his thrusts slow to a crawl, a lazy staccato roll of the hips. They share a soft, chaste kiss before Eren sits up to take stock of the situation. Mikasa gazes up at him, a soft smile and a blush of embarrassment returning to her face even only moments after cumming in his arms.

How the hell did I get here? The sight before Eren is heavenly, unthinkable, something that bastard Jean would have killed for in an instant. The great Mikasa Ackermann, 1st in class of the 104th, humanity's second-strongest soldier, and a girl who could kick his ass six ways from Sunday was stark naked, tied to a headboard by her trademark crimson scarf, lovingly gazing up at him. He was balls deep in Mikasa Ackermann! The girl who took down the female titan!

"What is it?" A small smile tugs at her lips as she rocks against him, jolting him out of his reverie.

"Nothing. Just… " Eren, realizing he had stopped thrusting leans in a little and begins again, planting his hands on either side of her torso. "You're beautiful." Mikasa shifts a little, pulling at her bindings with her arms. As her blush deepens, he feels a pang of affection. He recognizes exactly what she's doing, or at least trying to do – she would be burying her face in her scarf right now, if that same scarf hadn't tied her wrists above her. Speaking of her arms…

For a second, he zones out, hips working on their own, as he gets back into the groove. From up here, he can't tell where to concentrate – her legs, those long, lean, muscle-bound legs that could crush his head in an instant, her abs, rock–solid, he can feel rippling just beneath the surface, her breasts, pert, jiggling and swaying with each thrust, puffy nipples hard, her face, lips puffy, eyes unfocused, giving quiet, almost inaudible mewls of encouragement – well shit, why not go with the underdog competitor? Rising to a kneeling position, he slides his hands down her body to get two handfuls of toned soldier ass, raising her from the bed with a yelp.

"What're y-" Her question is cut short by a squeak from her own traitorous mouth. This new position, it's good, it's deep, hitting her right where it matters. Eren knows it, and a chuckle bubbles it's way out of his core.

"You like that?"

"Y-Yeah…" Her response is breathy, like she's straining or lifting or something. And she is, Eren realizes, still hammering away at her, because this position is hard. He looks down and sees how she's arching her back, tensing her core, and fuck if it isn't a sight, because he sees all of her beautiful ab muscles, rippling, rock-solid, he'd lick the sweat right off them if he was in a position to do so.

This beautiful, dangerous specimen, she could kill him in a second. He realizes it with a shock. There are a thousand things she could beat him at, and ten thousand things she had; for years he had known that she was stronger than he was, smarter too, a better soldier, a better person. But now, he looked down at her. Even if she was stronger, smarter, faster, right now, he was fucking her. The person who had outshined him every step of the way, who he had loved and hated and hated himself for loving – was beneath him, struggling to take his cock, staring deep into his eyes with a lust he had never seen before.

It turned him on, sure. But more than that? It made him feel very, very powerful. And he liked that.

"Say it." He can't really lean forward all that much while still maintaining this position, but he hopes the way he inclines his head gets the message across. His arms are starting to burn.
"What?" Mikasa's eyebrows furrow, a bead of sweat making its way from her temple to her chin.

"You're mine. Say it."

She takes a few seconds, and Eren, feeling vindictive, slows his pace a little.

"Ereeen…" she whines, drawing it out a little. After what seems like an eternity, she meets his eyes and adds softly, "I'm yours." They both breathe a sigh of relief as Eren releases her butt and drops her back to the mattress, the two locking into a deep, sloppy kiss.

Why did I ask that? Even after her confirmation, he still kicks himself for the corny line. Oh well, he thinks, trailing his kisses down Mikasa's neck to the collarbone. Guess it worked. He speeds up his thrusts again, and Mikasa acclimates with a whispered "yes."

From the collarbone he leaves a trail of kisses and light nips up to her jawline, where Mikasa gives a little gasp of pleasure. Next, he stakes a route up to her ear, giving a little bite to her earlobe, and she shivers around his length. He can feel her tensing up, a little more tension in her core, her legs that much tighter. For what it's worth, he feels the wave building too – an excitement, deep in his bones, coming out to play.

He leans back to admire his handiwork. A run of saliva trails from Mikasa's mouth down to her chin, and it seems she's too occupied to care. Short, messy onyx hair frames the beauty's face, most to the side but a stray lock squarely between her eyes, which gaze up at him adoringly.

"Eren, I.."

Did she say something? Eren continues his assault on Mikasa's pale neck, lost in her warmth, dedicated this time to giving her a hickey and staking his claim.

"Iwantyoutocuminside."

His hips stutter for a second, and he surfaces, rising to meet her feverishly hot gaze.

"What?" It's all he can manage, dumbfounded.

Mikasa's blush has spread to her ears, and this time, her response is barely above a squeak. "I want you to cum in me."

"Huh?" Alright, I definitely misheard her.

She steels herself for a second, then whines "I want you to cum inside!" Maybe it's a figment of Eren's horny-addled mind, but he could swear that her response echoes around the room.

They should cringe a little – it was pretty loud, and someone could hear – but, lost in each other's eyes, neither can bring themselves to care. Eren resumes his pace, and starts to feel his own orgasm bubbling up. Staring her down, he replies "Are you sure?"

He can't pinpoint her expression. She looks a little mortified, a little scared, very aroused, and a little something else… something like infatuation creeps into her eyes. "Yes," she whispers, loud enough just for him. "I want to be yours." Her eyes water, tears creeping to and clinging on her dark eyelashes. "I want it."

That dark feeling in his stomach surfaces again. Power. Over what? The little skeptical voice in Eren's brain sounds farther and farther away to the back of his head. Over her? Over myself? He pulls Mikasa's long legs up and hoists them to his shoulders, so she's almost bent in half under him. She gives a tiny, cute gasp but doesn't resist.

The feeling consumes him, an animalistic compulsion, like when he's a titan and operates on pure instinct, but instead of fighting, he's just fucking. Close enough, right? Muscles straining, sweat, grunts, moans, she's begging for him, he's praising her, he can't sound cool or powerful anymore because power isn't an affect but a feeling, and he feels it, it's rushing through his veins, it's in his blood and his mind and his soul, she's his, but he's hers too, and it's all building together.

In his blind, sex-addled fugue he lifts his eyes from their struggling bodies to her face and it's all clear. He loses himself in her eyes, those dark, beautiful, expanses, full of love and tinged with fear and spiced with obsession, somewhere between the alluring eyes of a doe and the terrified frenzy of a deer in headlights, like she can't believe what he's become, and bubbling up like the lightning in his being are memories in his soul, each jackhammer into her, each thrust and clap and pull a new remembrance, of when she stood up for him against those bullies, of when he wrapped her scarf for the first time and she looked at him with a sparkle in her eye, of when the first person to rescue him, after his first shifting, who put her head against his chest and heard his heartbeat was her, and he understood. Mindlessly, he plowed on, putting his entire body weight into every thrust of his fat cock into her poor little pussy, the wet claps of their fucking resounding through the room and certainly beyond, as if his grunts and moans and her squeaks and whines weren't already enough. His forehead planted on hers, he looks into Mikasa's eyes and knew she had always loved him, from her little private smiles, from the way she looked at him with soft eyes and the way she pawed that old scarf that he had given her all those years ago, but now he realizes, not with a shock or jolt, but progressively, like the orgasm building from his stomach to the tips of his fingers to his cock, railing her like there was no tomorrow, that before he hated her for her skill and her strength and smarts, he had loved her, and he had always loved her, he had hated and loved her, and this black-eyed, black-haired creature below him was special, he wanted to dominate her, to be her and be better than her and to be completely unlike her and to cherish her and to be lost in her dark, adoring, fearful eyes as he railed her into the bed –

Eren cums explosively, release wracking his whole body. He jackhammers into her, as fast as his burning hips could jam in and pull out, spurting cum into her poor little abused pussy as she climaxes around him. She'd pulled her hands loose somewhere in his rage and cradles his head lovingly, the two of them keeping eye contact, albeit a little unfocused, through the claps and grunts and spasms and whines and squeaks and trembles of two lovers burning through their release.

Eren's hips slow, stutter and stop. He backs up, pulling out his cock with a pop, to let Mikasa lower her legs to a more comfortable position, then collapses onto her, using her abs as a pillow.

They sit there in silence for a while, breathing heavily. She plays with his hair a little.

As Eren feels his eyelids begin to droop, he labors to raise his head and admire Mikasa's tired visage one more time. She's looking at him, eyes half-closed, a small smile tugging at her lips.

"I love you." Eren manages to get out, the words sweet on his lips.

Mikasa's smile broadens, just a bit.

"I love you too."