This feels completely different than cheating with Maiya.
It isn’t about him: his strength, his detachment, his commitment, they’re all irrelevant. Kiritsugu wonders if Saber is thinking about this as sex at all, because he certainly isn’t.
Perhaps more importantly, he doesn’t plan on asking her.
Saber braces herself on the mattress with her knuckles peaked toward the ceiling. She doesn’t touch him, doesn’t speak to him with anything but her eyes. They’re narrow, unamused. Kiritsugu remembers she is King, and considers accommodating that, kneeling, swearing, apologizing. It would only take a word.
He unfastens his pants instead.
Saber’s eyes glance down to Kiritsugu’s groin, then up again. She lifts her hands from the edge of the bed to loosen her tie, sighs, cracks her neck. Kiritsugu remembers how Nataliya moved, how she used to sigh in one short burst just like the air escaping from between her bones. Saber’s timbre is higher, her tone softer. Thinking about it distracts Kiritsugu long enough that he almost misses how Saber poises her mouth, how she leans forward to his hips.
Kiritsugu says nothing. She’ll have to get him hard somehow, won’t she? This has to be done, and they both know it has to be done, regardless of their feelings on the matter: feelings that Kiritsugu shouldn’t have and Saber shouldn’t have to ignore. So they do this. Her mouth is soft, testing, certain but not familiar. Her hands are smaller than Iri’s, shorter-nailed, conceptually callused. She holds him at the base, probably the inverse of the way she holds her sword, and works the fore past her lips, her tongue almost a hindrance like she’s used to smaller and deeper.
But it’s not like cheating with Maiya: there’s a coil of anger helixed with the heat around Kiritsugu’s spine, like a circuit opening without a spell to cast.
He swells, because the sensation is enough; he stalls, because when his hips twitch forward and her grip tightens near his balls, she bares her teeth and the mattress creaks. He has to grip her shoulder to stand. The fabric of the suit is cool under his palm, starched within an inch of its life.
Before he gets too hard, he makes the incantation. Prana flows through his circuits like the sharpness through a sleeping limb. He steadies himself on Saber’s shoulders, both now, holds only tight enough to feel the tension in his fingers. This will work.
Her teeth slip out again, and stay out this time. Kiritsugu looks down to the edge of the mattress, sees how white her knuckles are. She’d like to hit him or worse. He’d deserve it if she did. He shouldn’t have to, this is necessary, this is what it takes to win and Kiritsugu should have no qualms about doing what it takes to win. He should be outside himself, let his body fulfill this requirement and not care beyond the ability of his Servant to serve.
He should. He doesn’t. And more importantly, Saber knows.
His hips snap forward, instinct but not accident, and she chokes. He should, doesn’t, apologize, and when her nails bite into his thighs he doesn’t fight back or flinch away. Good, she resents it. Let her resent it and resent him as long as this gets done--
--no. He can’t think of himself as that kind of man and continue with the transfer. That’s not what this is. Is it?
He’s not sure who stops first, he or Saber, but his hips still and her mouth hollows and for a moment they aren’t touching at all. She pries her lips and her hand away from him, breathes, glares up at him from the bed. She knows. She knows what he is and what he thinks of this, and her, and she won’t pretend it’s anything else. It’s nothing like Maiya. Saber is the King of Knights. She is the commitment and strength that he’s supposed to have, the resolve to do what must be done no matter the cost to her honor. Or maybe she isn’t and Kiritsugu is right about not understanding his Servant at all.
He takes her by the shoulder again, but this time, he shoves her onto her back.
The mattress accommodates them both with more protest than he hears from Saber. He nestles his groin against her thigh to keep himself hard enough to do this, pulls her shirttails out of her pants, wrangles them open. She’s so small that he won’t be able to look her in the eye when they join if they do it like this. But for now she has his eyes, and she’s glowering at him with all the magic and hatred in hers.
She doesn’t touch him. Not when he primes her with his fingers, not when he widens the spread of her knees, not when he takes her by the hair to hold her in place. She doesn’t cry out or shift to adjust to his presence inside her. Her forehead wedges between Kiritsugu’s collarbones, scrapes up and down his chest as he thrusts. She doesn’t lie completely still, it would be easier if she did, but she moves just enough to abet him, match him, to speed this along. She knows what has to be done, and she does it, and she doesn’t let him forget.
When he finishes, he’s not sure whether she enjoys it physically or not. But knowing either way would make it worse, so he doesn’t ask, doesn’t check. His magic circuits ache the same way as his muscles and his knees, empty but still working, expectant. He pulls out, and sits back on his haunches. He can’t look at her, turns to the ceiling instead. The fan spins, but the circulating air doesn’t cool Kiritsugu’s face.
Saber works her legs out from under him, stands at the bedside, adjusts her clothes, and leaves. He doesn’t, shouldn’t, can’t watch her. But she’s restored, and that’s what matters, more than any false courtesy he could give, or she could give to him.
Not that he deserves it.