Disclaimer: I own nothing.

A/N: Originally written for ffxiii_kink. Lightning/Serah with the prompt being "Even if you're with him... You're all mine, Serah. Remember that...". The requester later decided to switch "You're all mine" to "You'll always belong to me" from which this fic gets its title. I'm unoriginal, I know. Second part this fic was not in the original version but was in the original idea. I just didn't include it because I wrote this for a kink meme. Contains not-too-explicit sexual situations and incest. Please click the back button if the idea disturbs you. Comments and criticisms are welcomed.

Story Note: Following Japanese version of the game, so Lightning's real name has the extra E and Snow calls her 'Nee-san'.

xxXxx

The wedding is tomorrow. She would be lying if she said that didn't unnerve her. Serah is getting married tomorrow. But, she reasons, they have waited long enough. After all the shit they went through, crystal stasis and all, you'd think the first thing they would do after being reunited is get married. But no, they waited the long months it took for Cocoon's civilization to start a new life on Gran Pulse without any mention of it. She had to say she was impressed. And plus she had already accepted it. It would be unfair to suddenly change her mind. So yes, they're getting married tomorrow.

Lightning watches as Serah does the dishes. It is their last night together. Serah will most likely move out –though just next door- after the wedding. It's still close, but not close enough. Even though work used to keep her away from home, it's comforting to know that Serah will always be there. She crosses over to the kitchen counter, picking up a cloth to dry the clean dishes. Serah looks her way and smiles.

She supposes that she has Snow to thank for this precious time together with Serah. He's out on his bachelor's party with the boys. Sazh, Hope, and his mates from NORA. It peeved her when she first heard of it. Bachelor's party? Somehow she foresaw a lot of drinking –for those old enough, anyway- and marriage jokes. But now it's a different story. However, Lebreau, who is a girl, didn't quite fit there so she was with them instead. Girl's night out. Very awkward, if she had to comment. It's like listening to both of them talk while she chips in a one-liner every now and then.

Though, no more of that. As though suddenly realizing that the sisters may want some time alone, Lebreau had politely excused herself and left, no doubt to join the boys. She supposes that if Fang and Vanille were around, they would be here too. But she's sure they're watching over everyone from Cocoon.

She suddenly notices that the dishes are done, and that Serah isn't standing by the sink anymore. She half turns, her sister's name at the tip of her tongue, when arms wrap around her waist from behind. Had those arms belong to anyone else but Serah she'd stiffen. But they do belong to Serah, so she merely turns her head and eyes the girl.

"Serah?"

Said girl presses her head onto her shoulder. "Thank you."

"For letting you marry Snow?"

Serah laughs small. "Hmm...for everything."

For everything? She didn't necessarily feel that she has done enough for Serah. Or that all the things she done was right. There are many things she would change if she could. Maybe then Serah wouldn't end up wanting to marry that idiot.

The arms around her tighten suddenly, as though Serah knew just where her thoughts were going and was reprimanding her for it.

"I love you."

Or letting her know that Snow or no Snow, things has not changed. And it's true. Serah still says it with the same conviction as she always had before Snow ever came into the picture. She drops the cloth and reaches for the hands on her waist. Dislodging them, she turns around and wordlessly, she reverses their positions, guiding Serah back against the counter. She smiles, and then closes in to kiss Serah's forehead tenderly. For a while it appears sisterly, a showcase of affection. But then…

She snakes her arms around either side of Serah's waist, reaching behind to grasp the counter, effectively pinning Serah to it. Her mouth travels down to an ear, slowly, tantalizingly breathing into it. Serah is tense already.

Her voice is low. "Did you lock the door when Lebreau left?"

Serah seems to struggle with the question before dumbly nodding her head.

She smirks, nuzzling the ear. "That's a good girl."

Serah noticeably reddens, even up to her ear. She snickers, and lets her teeth graze the outer shell, hearing a shaky breath leave the smaller girl. Then she pushes her knee at Serah's legs, parting them, and Serah gasps as her thigh presses against her core. Hands grab at her shoulders, and she purposefully ignores the clench-unclench action of the fingers, choosing instead to kiss a pale neck. She opens her mouth, but then she stops. No, she can't leave a mark. Not tonight anyway.

Her hands on the counter move to Serah's hips, tracing around her rear before effortlessly hoisting the girl up. She lets her sit on the counter just so, but doesn't let her get comfortable, an arm around her waist holding her upright. Serah whimpers at the position she's made to assume even as her arms hook around her shoulders for balance. But the whimpers quiets down immediately when she stands herself between Serah's parted legs, hand skimming an upper thigh. Then it goes under the short skirt –to touch Serah there.

Serah tries, and fails, to stifle a moan.

She traces her index finger up and down the length of Serah's centre, already wet through her underwear. The moans are getting harder to contain by the second, and Serah takes to burying her head on broad shoulders. She grins, finger still tracing, as she moves her mouth back up to the ear and whispers into it, feeling the small body shudder.

"Serah."

The head lifts a little at the name. She continues, mouth right next to her ear.

"Even if you're with him-," her thumb is tracing circles now, "-you'll always belong to me, Serah." Here she pauses, and almost growls the next sentence. "Remember that."

In an instant, Serah is twice as wet, fingers painfully digging into her back. But she pays it no heed, more interested in how much wetter Serah's become. She's known for a long time, through the years, through the experimentations, that Serah just loves possessiveness. It gets her off every time. Though she's almost sure that Snow would never practice it. And Serah will never tell him. Shame. What a waste.

She starts stroking harder, and feels those hips push at her, wanting more.

But she's not done yet.

"Say it."

Serah responds with an unintelligible noise.

"Say that you'll always belong to me."

More unintelligible noise as Serah strains to process her words. She doesn't make it easier, intentionally speeding up or slowing down her strokes.

"I…uh," Serah blinks rapidly, trying to steady her breathing enough to form the sentence. "I'll always…ah..belong to you."

Then as though feeling that wasn't good enough, the arms around her wrap tighter, and the words come again, clearer and more coherent.

"I'll always belong to you-,"

Lips meet her cheek, just below her ear.

"-Éclair."

Using her real name hammers it home. She pushes the underwear aside and slips into Serah, the other's body arching at the sudden entry. Legs wrap around her hips even as she pulls Serah's body against hers, hand in a steady rhythm. It doesn't take long. Serah's breath comes shallow, and within moments she climaxes, and it almost feels like her own.

She holds Serah on the way down, finding her lips to kiss just lightly at one point. Not too roughly, not too wanting. It's been a long day, and tomorrow it's big one. There is rest to be had. Serah slumps against her, tired, and sleepy, breath already coming slow. She smiles, hooking her arms under Serah's arms and knees, picking her up and carrying her towards the bedroom.

xxXxx

If she had been the type to smoke, now would seem like a very good time to whip out a stick. She's standing outside her house, breathing in the cool Oerba air, looking at the surrounding hills. After Cocoon's fall, the group had adopted Oerba as their new home. Together with family, friends, and some new faces, they had rebuilt and repopulated the abandoned village to its now thriving state. Homage to the two who should be with them even now.

She could see her breath forming. She never did like the cold. She had put Serah to bed just a while ago. The girl had fallen asleep almost immediately, curling in the sheets holding her hand. She couldn't remember the last time she just watched Serah sleep. She should have done it more. Nothing else achieves the level of peace that simple act did. But now Serah's moving out.

"What's with the troubled look?"

Not the voice she wanted to hear right now. She turns her head and sure enough, the 6 foot of a man had found his way next to her. "Party over?"

He scratches the back of his head, laughing. "Well, yeah. Gadot's out cold. Everyone else should get some sleep. Me too."

"You're drunk too."

"No, as in, I should get some sleep too."

"And I'm saying you're drunk too. You're red in the face."

"Oh," he blinks, and then he laughs some more. "Probably a bit too much."

This is the man who will get to watch Serah sleep every night from now on. She wonders if she made the right choice after all. She curls her lips and looks away.

"You didn't answer me," Snow presses on. "I'm getting married tomorrow. No place for such a look."

She snorts. "Maybe I'm troubled because you're getting married tomorrow. To my sister."

"Still antagonistic, are we?" he chuckles, obviously not too bothered by her comment.

She doesn't reply. It's not worth it anyway. The hills are more interesting than he is.

"Where's Serah?"

She had brushed Serah's hair while she slept. Serah had murmured her name.

"Inside, sleeping. She's tired."

He nods. "Getting some good rest, huh?"

But Serah also murmured his.

"Hey Snow."

He looks her way. "What is it?"

She holds out her hand, narrowing her eyes when he didn't seem to get the message. "Serah's crystal." She knows that even though Serah's safe and sound he still kept the crystal with him everywhere he goes.

Digging into his clothes, he fishes out the jewel and hands it to her, unquestioning. She takes it, and holds it firmly in her fist for a few seconds before moving it between her thumb and forefinger. Just like the time before. She brings it up to her eye level, examining the world through the reflections of the crystal. It's inverted. Upside down. But beautiful.

She drops the crystal back into her fist, turning to Snow. "Remember what you said to me? That this will be the last tear Serah will ever cry?"

His eyes dart from the crystal to her face. "Course I do. What about it?"

She gazes at the tear shaped crystal one last time, and then tosses it back to him. He catches it with ease. "I'm holding you to your word," she momentarily glances towards her house where Serah is inside sleeping. "If you hurt Serah in any way, I'll—"

"You'll kill me, I know," he cuts her off, smiling.

He appears sure of himself, but not in a way that is mocking her. She could tell from his tone that is in complete deference to her. He believes what he just said.

She smirks back. "No, I'll do worse," her smirk widens at his surprised expression.

"There's worse than death?"

"Much worse," she looks away, fixing her stare onto a single point in the distance. There is one thing she knows is much more important to him than life itself. It's the same thing she would throw away her life for. She'll never be his.

Serah called her name first.

"I'll take Serah away from you, and make sure you never see her again."

The following pause is just what she expected. She didn't have to look at his face to see his expression. But would he think she's joking? That wouldn't be wise.

He laughs, albeit uncomfortably. He looks at her, incredulous, then looks away again, still chuckling slightly. "You really know which buttons to push."

She smirks. Life without Serah isn't much a life at all.

Standing straighter, he turns to her. "There won't be a need for that," he assures. "I'll never hurt her."

Of course she knows that. He's a good person. Not perfect, not by a long shot, but he'd give his life for Serah. That's good enough. For the time being.

They lapse into a silence. Snow stretches his hands before turning towards her.

"Nee-san."

"Who's your sister?" she snaps.

He stops. "Uh, well you will be, tomorrow."

She sighs, glancing at him. "I know," Serah is really getting married tomorrow. "I just wanted to say that while I still can."

The big man grins and circles in front of her. "Want to have a drink with me?" he motioned towards the bar a little way down.

She raises an eyebrow. "I though you wanted to sleep."

He shrugs. "One more wouldn't hurt. I just realized we've never had a drink together before."

His smile is sincere.

"Sure, why not?"