Keith doesn’t do casual flings.
There are many, many reasons why he shouldn’t—he’s a prince, and the chances of being taken advantage of or just taken hostage are unfortunately high—but the main reason he doesn’t do it is that he just isn’t interested.
People have directed that kind of attention at him before. He doesn’t notice unless they’re being really obvious about it, but it doesn’t matter if he notices or not since, either way, he refuses to acknowledge it. He knows it’s not an attitude that wins him friends, but he doesn’t see how outright rejection is any better.
At least rumors of his coldness stop potential suitors before they even begin.
Point being—Keith’s not the kind of person who would ever claim a moment of love at first sight. He’s not the kind of person who would ever tumble into bed with someone he just met. He’s not the kind of person who would ever feel the word love on the tip of his tongue after the first touch of skin on skin.
He’s not that kind of person. He isn’t.
But the past hour has turned him into one, and he’s too busy enjoying it to hate it.
He gasps as Shiro’s teeth scrape his collarbone. The shivers down his spine are so at odds with the heat tearing through his veins, but they both threaten to tear his consciousness from his body. He tightens his grip on Shiro’s shoulders, desperately trying to stay anchored to reality.
They’re joined together in a way that Keith has never welcomed from anyone—never even wanted from anyone. He feels possessed. He feels like he should be stopping or slowing down or at least taking a moment to figure out what the fuck is going on and what he’s doing here, but as soon as he thinks that, he knows:
He’s here because Shiro’s here.
He’s here because the moment he saw Shiro smile, he felt an instant, searing attraction that he’s never felt before in his life. He’s here because he’d been walking alone in the dying sunlight when he’d caught sight of a tall, handsome stranger, and he couldn’t turn away. He’s here because they’d been drawn to each other, stumbling together as if magnetized and barely managing to exchange a few breathless sentences before they were kissing in the corner of the park, Shiro’s lips a balm soothing a loneliness that Keith hadn’t even realized he’d felt.
He’s here because the moment he had his arms around Shiro, everything inside him was screaming to never let go.
He wraps his legs tighter around Shiro’s body, pulling him up and closer, and stifles a sob at the way the change in angle drives Shiro impossibly deeper.
“You okay?” Shiro’s lips brush Keith’s ear.
His voice is soothing and rich; it travels straight to Keith’s core and makes him shudder. “Fuck.”
“Good fuck?” Shiro says, and he sounds amused now. His movements are shallow and languid; nothing more than a slow, steady grind. Like he’s just as reluctant to pull too far from Keith, even if too far is only half an arm’s distance away.
“Hnnng.” Keith’s torn between telling him to move and telling him to sink in, to anchor himself inside Keith’s body and stay there forever.
Shiro kisses his cheek, then his lips, and even the briefest contact sends the most amazing sparks skittering across Keith’s skin.
It’s been like this since the first time they’d kissed. Keith doesn’t even know how they made it back to his hotel room. He knows that they’d walked—the park is only a short distance from his hotel, which is how Keith had ended up there in the first place—but he’s surprised that they’d managed enough steps between their rushed, desperate kisses to make it back.
Now Keith presses his lips against Shiro’s and thinks—he would be happy to stay here for the rest of his life, melting under Shiro’s firm but gentle touch.
Shiro curls his fingers, blunt nails scraping against one of Keith’s side and sleek metal sending chills down the other, and Keith moans and reaches for Shiro’s hair and pulls him down harder, harder, harder, grinding their bodies together as he gives Shiro all he has. It’s longing and desperation, and Keith has no idea why he feels this, only that he does, and it’s going to consume him whole.
Shiro breaks away to kiss at the tears leaking from the corners of Keith’s eyes. He pushes Keith’s thighs further up and stays pressed close as he starts moving, so close that Keith can feel the heat radiating off his body. Every slow thrust forces out a quiet, shocked gasp from Keith.
“You’re so beautiful,” Shiro murmurs against the skin of his neck. “Can’t believe you’re real.”
Keith feels like he should be the one saying that. Shiro is—everything. Physical attraction, Keith has felt, even if he’s never acted on it. This isn’t it. Every time Shiro kisses him, the feeling of the press of his lips is secondary to the mark Keith feels it leaving on his soul.
The thought comes from nowhere and lingers in his mind—this unexplainable attraction could easily be the result of a soulmate bond. The winged serpent curled at the nape of his neck feels hot.
“Shiro,” he gasps. “Wait, I—“
Shiro freezes, hovering over him. “Are you okay? What’s wrong?”
“No, nothing’s wrong,” Keith says, and struggles with how to ask the question. “I just—Your soulmate—”
“Oh.” Shiro relaxes, then shrugs, smiling wryly. “Don’t worry about it. I don’t have a soulmate.”
I think I could be your soulmate, is what Keith wanted to say, but now the words die in his throat, the same way his heart drops.
He wanted that chance.
He didn’t actually realize how much, not until Shiro said the words, and he feels a bit silly for it—he’d just had the thought less than a minute ago, what reason does he have to get so upset about the fact that it hadn’t worked out? It isn’t as though he’d built up a fantasy about it.
But maybe he had. Maybe in that split second, he’d built up an idea of what the future could hold for them.
It’s better, he thinks, for it to be impossible. He’s a prince of Daibazaal on a diplomatic mission. He’s only a few hours off of his sixteen-hour flight from the other side of the world, where the Galra have lived mostly in isolation. He can’t afford a human as his soulmate, let alone a human he hardly knows.
His life isn’t meant for that.
“Are you all right?” Shiro says softly. The backs of his fingers are curled against Keith’s cheek, and his face is so, so careful.
Keith nods. Fuck, he thinks he’s crying again. He hadn’t realized how much disappointment could hurt. How much rejection could hurt—not that this was even a real rejection.
Shiro starts moving—to draw back, Keith realizes, and he clamps down with all his limbs to keep Shiro pressed against him.
“Okay, okay, I’m right here,” Shiro murmurs, rocking against him. It’s perfect, and Keith shudders. “What do you need?”
“Kiss me,” Keith says.
He half-expects the electricity to be gone, but when Shiro kisses him, everything inside him still sparks to life. They’re not soulmates, and Keith doesn’t understand what else it could be, but he’s done trying to figure it out.
He wants this—wants Shiro—more than he’s ever wanted anything in his life, and he’s going to enjoy it while it lasts, with everything that he has.
He pulls Shiro deeper into him, rocking their bodies together, and Shiro moans into his mouth. Shiro’s noises are feeding a thirst in him. His low groans make Keith’s belly pool with molten heat, but when his sounds become high and needy—that’s what makes Keith desperate in return.
Shiro’s rutting against him desperately, and Keith is trying to get him to move faster, deeper, but neither of them wants to stop kissing, and Keith has his hands on the back of Shiro’s head and neck to keep them in place, and Shiro’s hands can’t decide if they want to run all over Keith’s body or grab onto his hips to guide their fucking. Shiro slips out once, then twice, and both times he reaches down without breaking away and guides himself back in.
Keith doesn’t break away until he’s actually starting to feel light-headed, and Shiro takes the opportunity to turn his face down into Keith’s neck and bite down at the junction of Keith’s neck and shoulder.
“Oh fuck,” Keith gasps, and for one blissed-out moment he thinks he’s come just from that. He hasn’t, but in a way, he feels like he has—the friction of Shiro’s skin against his fills his mind, and he feels oversensitive from each thrust of Shiro inside him. “Shiro,” he says, “Shiro, Shiro, I need—“
Shiro licks at the spot he bit, then trails his tongue the rest of the way up Keith’s throat, making Keith shudder. “What do you need, baby?”
“I need—“ Too much. To come. For Shiro to come. For Shiro to kiss him again. For Shiro to hold him close and to never let go. “I can’t—“
“You can,” Shiro says, and it’s unfair how he can sound like that, firm and gentle and commanding and arousing all at once. He scrapes his teeth against Keith’s jaw, and Keith whines softly. “Tell me what you need, Keith.”
“Fuck me,” Keith says. “I need to feel you, please, fuck me—“
It doesn’t make any sense, as a request. Shiro’s already fucking him, after all. But Shiro doesn’t look confused, or ask him to clarify. “Okay, baby,” he murmurs against Keith’s skin, and then he throws Keith’s legs over his shoulders, uses his hands to tilt Keith’s hips back, and well and truly fucks him.
Keith doesn’t know what to do with his hands. They twist in the sheets as he cries out, but—he wants them on Shiro. He reaches out, fingers scrabbling at the sides of Shiro’s ribs, as everything inside him crumbles to pieces.
It’s a pleasure he can’t describe, one that robs all thoughts from his mind and pushes him beyond words.
“Keith,” Shiro breathes, “Fuck, Keith, I lo—”
Keith surges up, grabbing onto the back of Shiro’s head and kissing him desperately.
Don’t say it, he thinks. You’ve known me for one night and you’re not my soulmate, you don’t even have a soulmate, don’t you fucking dare say it.
Shiro makes a soft noise into the kiss, and then a frantic one as he begins to shake, but Keith curls his tongue against Shiro’s and swallows down his voice.
He doesn’t want to hear what Shiro will say as he comes.
Keith doesn’t let go until Shiro is sated and heavy against him. Shiro studies Keith’s face as he pulls back, but all he does is murmur, “Relax,” as he presses a hand against Keith’s hip to hold him down as he pulls out.
It almost feels bigger on the way out, and Keith’s breath escapes him in a stutter as Shiro pops free.
Shiro studies him for a moment, then, keeping his hand planted on Keith’s hip, bends down and takes Keith into his mouth.
Keith shouts and bucks up, and Shiro’s other hand comes up to keep Keith held firmly against the mattress as Shiro works him over slowly with lips and tongue. There’s a pressure building in Keith’s mind, the same way it’s building in the rest of his body. He thinks he might actually explode with it.
Shiro squeezes his hips, hard, and Keith screams.
Time passes strangely for a while.
It could’ve only been seconds—in fact, it probably was only seconds—but Keith feels like he’s coming for hours. He can’t think, he doesn’t even know if he’s breathing, and he thinks there’s a good chance he actually passed out for a bit, but when he comes to, Shiro is curled around him, hand still languidly stroking his cock, and Keith weakly rolls his hips away because he is going to die if Shiro keeps that up.
Shiro gets the hint quickly, and instead slides up to kiss Keith slow and deep. Keith accepts it for a moment before turning away and groaning. “You’re too…”
“Alive,” Keith grunts. He’s halfway to sleep, and he thinks he could stay there for days.
But Shiro—he’s bright-eyed, with a soft smile on his face. It’s not normal, Keith thinks, for a man to have that kind of face when the rest of his body is… like that. Enormous and sculpted, with a tattoo of a rose over his heart—his body looks like he could snap Keith in half with barely a thought, but his face looks like his sole purpose in life is petting kittens.
“That was good sex,” Shiro says, in a tone that’s far too chipper.
Keith scowls at him. “Are you an incubus or something?” That would explain the body, and the ungodly energy.
Shiro blinks at him. “Are those real?”
“You tell me.”
“I’m a little too mortal to be one, I think,” Shiro says dryly. “How do I know you’re not the sex demon?”
“Because I’m dead,” Keith says. “You can’t kill a sex demon with sex. That’s against the demon rules, or whatever.”
“Of course.” Shiro pecks his cheek. “The demon rules. Can’t forget about those.”
Keith shifts uncomfortably, because—it’s too comfortable. Everything’s too comfortable. He’s not supposed to have casual sex, and he’s pretty sure he’s definitely not supposed to laze around bantering with his partner afterward. They’ve known each other for hours, but the weight of Shiro’s arm over his body has the easy familiarity of years. Keith’s chest tightens. It’s unfair.
“Hey, are you okay?” Shiro says, running his thumb across Keith’s cheekbone. It feels wet.
“M’fine.” Keith swipes at his eyes. “Just tired.”
“I’ll clean us up,” Shiro says, rolling away. “Can I use any of the towels in your bathroom?”
“Go for it.”
It’s when Shiro heads towards the bathroom that Keith sees it.
Nestled on the curve of Shiro’s lower back is a mark. He really only sees it for a few moments before Shiro disappears into the bathroom—not enough time for anyone to really capture the details, but Keith knows it intimately.
The ouroboros—a winged serpent, half-white and half-black, curled in a circle as it opens its mouth to devour its own tail. It’s a common enough symbol that Keith could pass it off as another tattoo, if not for the symbol of his mother’s family, the House of Marmora, nestled in the center.
It’s his soulmate mark. He’s sure of it.
But Shiro had said, easily, that he didn’t have a soulmate. There are reasons people lie—to protect themselves if they fear being taken advantage of, like Keith, or if they would prefer not to believe in the concept of soulmates in the first place. Either way, the fact that Shiro lied means that he doesn’t want his soulmate to be Keith.
If the disappointment he felt earlier was painful, the rejection that he feels now is devastating, crawling down his throat and squeezing his heart in a grip so tight he thinks it might shatter.
When Shiro returns with towels, all Keith can think is why did you lie? When Shiro discards them into the hamper and crawls back to bed, dropping a sleepy kiss on Keith’s forehead, all Keith can think is why did you lie? When Shiro wraps his arm around Keith and murmurs a quiet goodnight, all Keith can think is why the hell did you lie?
But rejection clogs his throat and keeps him from asking the question, because he’s already drained and he knows that hearing the answer will only break him more.
Tomorrow, Keith decides. He’ll put this out of his mind and just enjoy it for a night.
He curls closer to Shiro, turns his head up to press a kiss against the line of Shiro’s jaw, and settles in for sleep.
They’ll talk about it tomorrow.
It’s not as though he’s not keeping his own secrets. Keith looks human enough that Shiro probably hasn’t noticed he’s part Galra, and Keith knows that Galra aren't exactly well-loved by the humans.
When Keith wakes up in the morning, sunlight streaming through the shutters and across his face, he encounters exactly what he expected when he made the decision that he did.
The bed beside him is empty.
Shiro’s already gone.