“You’ve been under daily medical supervision for the last six weeks,” Keith says flatly.
“Well, yeah, but—"
“And it’s not like you can get me pregnant,” he adds flippantly, expecting either another weak protest or (preferably) a laugh. Instead, Shiro’s dick twitches emphatically in his hand, a fresh bead of precome rolling slick and shiny onto Keith’s wrist.
They both freeze, but Keith keeps his hand right where it is. Shiro’s eyes go wide, the flush of his arousal (and, okay, a little bit due to the beer they’d both been consuming earlier, but whatever) darkening into embarrassment.
“Keith, I—" he starts, but no, absolutely no way, Keith isn’t going to let him freak out now, not when Keith finally has his hands on Shiro’s dick; it’s not happening. Especially not when Shiro’s flight suit is hanging off the back of the door, ready for the morning.
“That does it for you?” He asks, careful to keep any judgment out of his voice. He pumps his fist on Shiro’s cock once, just to emphasize that part. Shiro somehow gets even redder, the flush spreading down his chest. His Adam’s apple bobs as he swallows hard.
Keith tilts his head a little, lets his eyes go half-lidded and his lips curve.
“You wanna knock me up, Shiro?” He asks, probably not quite managing ‘sultry’ but giving it his best effort.
(If he ever got this chance, he didn’t want to screw it up due to his own inexperience. Keith would never admit to having practiced, but he’s still weirdly proud of the purring undertone he finally achieved.)
Whatever tone he managed, it’s enough to make Shiro groan, and his cock is practically throbbing in Keith’s grasp, leaking precome all over the place. It’s fucking hot, and he has to reach down with his other hand and stroke himself a few times to take the edge off. This wasn’t on the top of Keith’s favorite porn kinks, but it’s definitely working for him right now.
“Fuck, Keith,” Shiro breathes, and he’s watching Keith touch himself so Keith makes a show of it, arching his back and dragging his slick fingers from the base of his cock up along the trail of his pubic hair toward his belly button. He splays his fingers out there, palm flat.
“It’s so empty,” he pouts, ducking his head a little so he has to raise his eyes to catch Shiro’s gaze. He offers the tiniest mental prayer to anyone listening that he isn’t about to go too far with this. “Will you put a baby in me, Shiro?”
“Keith,” Shiro groans as he reaches up and hauls Keith down into kissing range with one big hand scruffing his neck, lips and tongue hot and wet against Keith’s. He finds Keith’s hole with the other hand, two blunt fingers stroking the tight ring of muscle.
Keith flails with his free hand for the little bottle of lube that had started this conversation in the first place, unaccompanied as it was by anything even resembling a condom.
“Want you to fuck me,” he bites out against Shiro’s lips between kisses, fumbling one-handed with the bottle, “I wanna feel you tomorrow, want you to fuck me so full I can feel it for the whole year,” he gets the cap open, spills the lube all over the sheets but doesn’t care because there’s enough on his fingers that he can reach behind himself and add his fingers to Shiro’s, can spread it over his hole to ease the way for Shiro’s fingers to sink into him, “I want you to come inside me, make me big and fat with your baby—” Shiro adds a third finger, and the sudden stretch of it is enough to cut Keith off with a groan. Their kisses are sloppy now, practically just mouthing at each other. Shiro’s teeth sink into Keith’s neck, not hard but enough that he can feel it, enough that it might bruise.
“They’d all know,” Keith pants against Shiro’s cheek, tasting his sweat. “They’d all know it was you who knocked me up—"
Shiro takes his fingers away, and Keith can’t help but whine at the loss as Shiro rolls them over. His eyes are so dark, his skin flushed and glistening with a thin sheen of sweat. He’s beautiful, and Keith is so in love it hurts. Shiro leans over him on one elbow, and his fingers knot in Keith’s too-long-for-regulation hair, tilt his head back so Shiro can mouth along the column of his throat before kissing him, wet and messy.
“You want that, baby?” Shiro asks, his voice husky in a way that bypasses Keith’s brain and goes straight to his dick. Shiro’s lube-covered hand snakes into the space between their bodies, palming Keith’s abdomen. “You want me to breed you?”
Keith shudders, so turned on he thinks he might actually explode if Shiro doesn’t get his dick in him immediately.
“Yes, fuck, oh my god Shiro,” he babbles as Shiro gets to his knees, spreading Keith’s thighs wide as he lines himself up. The pressure of his cockhead against Keith’s hole is intense, and he grits his teeth without thinking.
“Gotta relax, baby,” Shiro murmurs, pausing to rub circles into Keith’s belly with his free hand, brushing against the tip of Keith’s dick with his thumb. Eventually, Keith does, and the flared head of Shiro’s cock pops inside. It feels huge, and Keith scrabbles at Shiro’s arms, his chest; any part he can reach.
“You’re so big,” he breathes, huffs an amazed laugh, “Holy shit.” The laugh turns into a groan as Shiro pushes the rest of his cock inside in one slow, smooth thrust.
“You feel so good,” Shiro tells him, hands bracketing Keith’s waist, “So tight for me.” He pulls out just a little, just enough that Keith can feel the way his body resists it, tries to keep Shiro inside. The feeling of Shiro fucking into him again is a revelation, and the next thrust something akin to nirvana. Nebulas spin and stars explode into being and Shiro is fucking him, not fast or hard but with deep, even thrusts that have him gibbering nonsense when he can even manage anything close to words.
Keith loses himself in it, lets Shiro guide his hips while his every sense focuses down to the place where their bodies come together. It doesn’t take long for Shiro to find his prostate, to find the angle that lets him hit that spot every time he fucks into Keith, and he makes no effort to quiet Keith’s howls when he does.
“That’s it,” Shiro says, voice and breath choppy with the rhythm of his thrusts, “Let me hear you, baby; let me know it feels good.”
“So good,” Keith practically sobs as Shiro wraps his hand around Keith’s dick, so wet from his precome that it slides easily through his fist. “Shit, fuck, fuck, Shiro I’m gonna come—“ he makes a vain effort to smack Shiro’s hand away from his dick — he doesn’t want to come yet, he wants to stay here forever, with Shiro above him and in him, every inch of his skin electrified — but Shiro doesn’t stop stroking his dick, fucking him, lighting Keith up everywhere they touch.
“Yeah,” Shiro encourages as Keith’s balls tighten up, his cock somehow getting even harder as his orgasm builds, “Fuck, Keith, let me see you, baby,” and Keith could never deny Shiro anything.
He comes so hard his vision goes white, toes curling as Shiro keeps stroking him, keeps fucking him, drawing out his orgasm until Keith is reduced to a shaking puddle of slack muscles and jizz. And Shiro is still fucking him, his cock driving deep into Keith’s pliant, oversensitive body, chasing his own climax.
“Shiro, Shiro, fuck,” Keith chants. Shiro has him bent nearly in half, larger frame arched over so he can fuck down into Keith; he’s caged in by Shiro’s arms and covered by his body and the whole world twists and he means it, means every bit of it when he says, “Fuck, breed me, Shiro, get me pregnant, I want it so bad—"
“Keith,” Shiro groans his name as he buries himself as deep inside Keith’s body as he can, the wet heat of his come flooding Keith’s insides. It’s perfect, it’s glorious, the bliss on Shiro’s face as he comes, and for a delirious moment Keith wishes he really could get knocked up; that Shiro would leave a little piece of himself behind, in Keith.
Shiro rolls them onto their sides as he slips his softening cock from Keith’s body, careful not to crush him as Shiro collapses bonelessly to the mattress. Keith closes what little gap Shiro left between their bodies, uncaring of the drying mess on his belly or the slickness between his thighs when Shiro is right there, being so kissable. Shiro’s arm comes around his ribs, pulling him in close, and he noses into Keith’s hair as they settle against each other.
Keith manages to hook the edge of the top sheet with his toes, which is enough that he can drag it up over them. The ache in his lower body makes itself known as he curls to reach the sheet with his fingertips; sitting in the simulators won’t be fun for the next few days, but he plans to savor every moment of the discomfort.
By the time he manages to wrangle the sheet, Shiro’s breathing is already beginning to even out into sleep, and it gives Keith a chance to study his face in the dim moonlight. Not that he hasn’t already memorized every angle and plane, but. The morning is already too close, and Keith hates it. He wants to stay awake to keep it from coming, but his eyelids are suddenly too heavy, and Shiro is warm beside him, and he falls asleep with his head pillowed on Shiro’s bicep, somewhere between one breath and the next.