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Sometimes, if he presses into Nai just right, Nai presses back.
It’s the edge of morning, right at the point when the dark of their little haphazard room carved out of the rubble is at its deepest. Their bed is warm; everything else is cold in the desert as soon as their suns set. He used to wish they still had the lined jackets Rem gave them, but they’d have outgrown them by now. In the last few months, Nai’s put on enough size to serve as a functional heater, mattress, and pillow, all in one. His arms wrap loosely around Vash to hold him close and hot through the night. It’s perfect.
It’s perfect, except that sometimes lately, Vash gets restless.
He can’t shake the feeling that he needs to be doing something, somewhere, but there’s no leaving bed without waking up Nai. For the first few weeks he satisfied himself by stuffing his face into Nai’s chest and letting the familiarity of his smell calm him. It helps enough. He never brings it up.
On a hot day, they spend too long out and don’t get back until late. It’s Vash’s fault. They get separated in a debris field and Vash gets distracted following what he thinks are human footprints. By the time Nai finds him, Nai’s gone that way he gets now when Vash is too long out of sight or too close to danger: big wide eyes, pupils shrunk to pinpoints in the blue, breath coming hard.
That night, he sleeps with Vash under him, his heaviness inescapable, and every hard corner of his body pressing into Vash’s. The edge of his hip finds the hollow between Vash’s legs, and Vash can’t sleep.
Eventually he has to throw his arms over his eyes to stop himself from feeling like he’s going to start crying, and he can’t figure out why. Only that he needs something and he’s not getting it, and being close to Nai makes it worse and better in turn, breath by breath.
The next night is the same. Except, when Knives falls asleep on him, he’s higher up the bed, off center and pillowed on his own arm. When the hollow feeling comes, Vash grips him closer and rolls them a little, his leg around Nai’s waist. Something presses back; a new and terrible pleasure flickers up his spine. His breath goes short. He presses impossibly closer, it feels impossibly better, and the tension in him spins out. It’s better when he moves, and the heavy thing between Nai’s legs only gets harder as he does. The progress is slow. It gets better, and better, until he can hear that his breathing is too loud. When he reaches the peak, he falls right off it.
In the morning, Nai’s gaze follows him with an odd set to his mouth. But if he knows what Vash has done, he doesn’t say.
He can’t know. If he did, Nai would already be gone. He would leave Vash in the dust and ruin. He would know that none of this, not a moment of it, was worth it. Nai is the smart one, the swift one, the one who always has a plan. He talks about philosophy sometimes in the quiet of their shared solitude as they wander the desert. His voice has gained dimension, deepness. Vash’s still has its pitch. He’s taken to leading Vash, and Vash lets himself be lead.
This is the first thing he can recall doing without Nai’s permission. He wonders, nightly, how it would feel without the double layer of cloth between them. Once, he tries with his own hand, to see if he can mimic the pressure with the heel of his palm or the press of his thin fingers, but it isn’t the same. It’s Nai he needs, and Nai’s hardness, and Nai’s heat.
Tonight, when he wakes, it’s to Nai pressed into his back, and the heat between his own thighs already molten.
Vash turns in his grip, slowly, gently, hardly breathing. Nai shifts once, so used to Vash against him that the feeling of Vash reorienting to gather Nai in his arms doesn’t do the slightest to rouse him.
He lets himself steal a moment in the dark, peering at Nai’s face. He’s peaceful in his sleep. His hair sticks out here and there and lays across his wide forehead. Vash pushes the strands from his brother’s eyes and then hooks his arm around Nai’s neck.
Guilt rolls through him. But it’s only for a little while. A little friction, a little relief.
But tonight, it feels different. It was laundry day; their clothes are hanging off a line outside. Vash has on a rag of a shirt they found in the ruins and Nai is wearing nothing at all.
He’s never been bare against Vash before and the newness of it has him red down to his toes at the first shift of their bodies. Nai is already hard and wet against his stomach. Vash slides a little, an easy back and forth that he feels born to, like all his tendons and muscles were made to do exactly this.
It usually doesn’t take him long. Well. Longer, lately. He can tell it’s going to be short tonight. At the start, it only took him a minute to find his peak, but the more he does it, the more it seems to take. One night he rode Nai’s thigh for what seemed like hours without Nai waking before he finally spilled some foreign wetness between them—and spent all the rest of that night praying it would dry before morning.
He slides against Nai again, but he’s getting sloppy. The head of Nai’s cock slides into his slit and against the entrance he's only ever tested with his own thing fingers. Vash makes a sound he doesn’t mean to, and then bites the hand of the arm he has around Nai’s neck to stop himself from doing it again. What would Nai do if he woke up? Rem said—Rem said a lot about this, about what brothers could and couldn’t do, when she found out they were sharing a bed. Sharing everything.
Nai shifts in his sleep.
The pressure increases. Nai tips Vash to his side in his sleep. Lips press against his cheek; Nai’s cock nudges his entrance again, this time without Vash moving against him at all. Vash holds his breath in terror, but Nai’s breathing doesn’t change. He’s still asleep. Somehow, he’s still asleep.
He could push Nai off. No; he has to push Nai off. He has to. This is too far. Rem warned him about this. But his heart is in his throat and it’s never beat this hard; he’s never wanted anything like this. Nai moves again. Moves his whole body.
The angle changes, and his next mindless thrust is dead on. The head of his cock pops inside Vash’s willing body and stays there.
Vash slaps a hand over his mouth, staring up at the stars, tears leaking from his eyes at the sudden pressure. Oh, god, Nai.
A rumble of breath huffs against his cheek, and he can feel it in Nai’s big chest, and then his hips flex and drive up. He makes a sleepy sound. Vash wonders if he’s going to bite through his own hand. His brother is big, so big, and the tight motion inside Vash feels like it's coming up against a wall. Nai’s hand drags against the bed and then against Vash's side and to the curve of his ass and squeezes and kneads the muscle there. There's still time for Vash to end it. And he has to. This can’t happen between them, even though he's dripping around the weight inside him.
With his moment of clarity he tries to ease himself up the bed and away, but at the first pull of his body against Nai's cock, the grip on his ass firms and holds him there. Vash’s breaths start coming in shallow, panicked pants.
Nai moves up into his forced stillness in a slow, lazy press. Vash aches, and then something in him gives. The brief burst of pain is nothing compared the fullness. It’s big and too much, too fast, just right. He feels hot. Inside is so much better. When Nai is as deep as he can go in his sleep, his hips jerk back, and then in again. In and out.
Vash forces himself to be silent against the risk any sound will wake Nai, feeling his face grow more and more heated, his thighs sweating and trembling in their hold around Nai’s waist. Blood wells against his lips, where one of his fangs has punctured the skin. It’s the sound that’s the worst. It’s so loud in the quiet, so wet. Do humans get this wet? he wonders as Nai uses Vash’s body the way Vash intended to use his.
After a very long time, what seems like so long a time that Vash is sure he’ll pass out before anything changes, something in him goes strange. He’s reached this edge before on Nai’s body a dozen times at least, but this time it comes on him different. He feels like he’s at the cliff, but this time when he falls off, he fears he’s going to break. He holds Nai tighter, trying not to cry.
You cry too much, Vash.
It rises and rises. Hot tears slip out. He keens; the sound slips out of him. Nai’s cock bumps in too deep, so deep it hurts, and this time the sound that escapes Vash’s bloody lips is loud.
Too loud.
Nai stops moving. His breath deepens, and then shallows. “Vash?” he says sleepily, and then louder and firmer, “Vash?”
He can’t say anything. His arm around Nai’s neck is damning. His legs around Nai’s waist are damning. The fact he’s dripping around Nai’s cock, his body pulsing around him—they can’t come back from this. Nai releases his hip and tries to pull back, but Vash keeps his face pressed tight to his shoulder. He can’t see it, can’t look at the disgust on Nai’s face.
For what feels like minutes but can only be a few breaths, they stay that way, suspended. And then Nai murmurs in his ear, “You need this,” and pushes into him in full.
It isn’t how it was before. Not clumsy, not haphazard, not accidental. Nai puts power behind it, enough that Vash tips fully onto his back. Nai resettles between his legs, and his hand returns to Vash's hip, grip firmer and directed, and Vash realizes what this is now.
Nai is fucking him.
He sobs; Nai makes a soothing sound. His motions are so directed they seem practiced, designed to ruin. That’s what he’s doing—he’s ruining Vash. He’s sore already from the prolonged contact, from the width of the thing Nai is pressing inside him, and it worsens as he presses deeper, into a spot he wasn’t hitting before. Vash grips Nai’s back, not sure if he wants to draw blood, push him off, pull him closer. Nai feels him move and bends his head to Vash’s neck. His lips find the corner of his jaw, and then the pulse point on his neck, sucking so hard it hurts.
When humans love each other, they kiss, Rem said. Only in movies? Vash asked. Rem laughed. No, in real life, too. And then she’d caught Vash in Nai’s lap and their mouths pressed together and—and nothing was the same—
“Nai,” he pleads. “Nai, we can’t.”
Nai’s rhythm stutters. “Shh,” he soothes, and resumes at the same steady pace, now dragging the head of his cock past a point that feels like it must be in the very middle of Vash with how deep it is and how much it makes him ache.
“No—Nai, stop—”
For a time it seems like Nai won’t answer. He’s fucking Vash the way he does every new task he attempts: perfect and steady on the first try. Vash’s big brother, smarter and stronger and bolder and when he replies at last, it’s with a deeper voice than Vash has ever heard him use. “Stop? Why?” The hand not on his hip falls between them, tracing where they’re connected, Vash’s abused entrance and the bundle of nerves above it. He drags his fingertips through the wet and draws a little circle. “Why, when you’re so wet for it?”
“Rem said—”
“'Rem said,'” he mocks, and he pushes Vash from his grip around Nai’s shoulders roughly and back into the bed. This way, Vash is forced to look at him in the slowly dawning light. All he can see is the trail of blood on Nai’s lip, where his fang has bitten through it, a twin to match the blood Vash knows is running down his chin.
He wasn’t asleep, Vash realizes with spike of panic.
Nai uses their distance to reposition himself between Vash’s legs and force the angle higher and tighter. His pace renews, slower and harder. Vash is past his tears, almost past coherence. Rem said that humans have twins, too. Rem said, for them it was different. Rem said, Nai really loves you, but the way he looks at you…
He wasn’t asleep. Was he ever asleep?
Nai bends in close to him. The kiss is precise, open mouthed, like he’s been waiting for the chance for so long he’s memorized what he would do and practiced it in his head. Tongue finds tooth; the salt and tang of blood is overwhelming. He drags his mouth to the corner of Vash’s, and then to his ear and whispers, “Rem said I couldn’t have sex with you. She—she said it like I didn’t know what it was, like I was too young to get it. Like she was scared.” He laughs, and it comes out like a moan, right against Vash’s cheek. Nai is sweating. Vash realizes he is, too, that every spot between them is slick now and the place where Nai is pressing inside him has gone almost numb except for the way Vash’s body keeps moving against his will and the sound of their coupling has turned into a sharp staccato like when Nai presses piano keys too hard.
His fingers are still there between their legs, working Vash, though he can’t feel that either. His eyes keep going out of focus, rolling back. When Nai kisses him again, he tries to kiss back and misses, his mouth sloppy against Nai’s tongue.
“There we go,” Nai says approvingly. “I told you, you need this.”
“But…”
Rem said…
You’re too young. Her fingers tucked Vash’s hair back from his cheek, behind his ear. Even if you feel that way, too, you’re too young. You don’t understand yet. And Nai and you—if you did that together—something could happen. And you’re so young, Vash. Promise me. When you get older, you’ll understand, okay? And: You’re so young, again, like her heart was breaking, and Vash wanted to tell her that it had only been a kiss.
He isn’t young anymore. Not even by human standards.
And what, he wonders, was she so scared of? Fear feels distant. The world is losing its edges. Nai is everywhere around him, in him, all he can smell or hear.
“I’m close,” Nai murmurs. To what, he doesn’t say. They’re already close, Vash wants to tell him. If he wants to get closer, they won’t be able to manage it. Maybe something is wrong with Vash, that he’s this wet, like all of what he is is leaking out of his pores the same way Nai can put his hand into sand and make water come up around his fingers.
His breaths turn into little breathy hiccups and sobs he’s horrified his body can make, but he can’t stop making them. Nai noses at his cheek and catches them. And all of a sudden, he knows what Nai meant by close.
He was right: this time, when he reaches the edge, it does break him. It breaks him and he can’t breathe. He can’t make a sound. His back arches so hard and deep he thinks that it will snap in real time, but Nai holds him through it. He wraps his hands around Vash’s hips and squeezes and pulls him in—closer. There, closer, that’s what he meant. They can be closer, after all. Everything inside him is warm then, and Nai’s cock is pulsing inside him the way Vash’s body is pulsing around his.
For a moment, the world is gone. He can feel nothing, and think nothing, and see nothing. This is a mistake, he realizes, and it’s his fault. Would Nai have lost his patience one day and held him down and did this? Or, if Vash had maintained his distance, would Nai have honored it? It doesn’t matter. They can’t come back from this. A hundred years from now, he’ll be thinking of this, needing this.
Nai rolls his hips lazily, and again. Vash isn’t sure what’s supposed to happen. His skin is prickly and his eyes feel swollen. Now that the numb pleasure is wearing off, he’s realizing he’s sore in places he didn’t know he had.
“Ugh, st—stop,” he says weakly, pushing at Nai the way he does when Nai is too heavy at night, too sweaty at the end of the day, too close.
Nai laughs at him and grabs a hand, but the motion of his hips continues. He brings Vash’s hand to his mouth and kisses his palm, and then licks up his fingers as if Vash is a meal. There’s blood smeared on his chin and lips; Vash isn’t sure whose now. And Nai is so beautiful like this, so terrible like this.
“I can’t stop now,” he says casually. He cups Vash’s hand to his cheek and leaves it there; Vash lets his fingertips run through Nai’s hair. He’s hard again inside Vash, and moving again.
“We were born for this,” Nai confides, and closer: “You were born for me.”
Vash believes him.