When he finally shrugs off what little he has left of his honor and shoves the Knight of the Flowers against the wall of the Red Keep, Jaime thinks he's probably the more surprised of the two. He can feel Loras smirking against his mouth, grinding up against his knee. The brazen impudence is possibly what turns Jaime on the most.
He pulls away, can't decide whether or not to glare or smile at the boy, so he just leans in to kiss him again. His tongue is slick and fast, sliding its way into Jaime's mouth with what must be an oft-practiced motion. Loras moans something against his lips that sounds like, but Jaime really hopes isn't, "Renly."
Jaime dislikes that - dislikes it the same way he does Loras's every sideways look at Brienne, every hitched eyebrow and cross of his arms, every time he says or does something that Jaime can hear echoing through his own lips from summers past. He thinks of calling him 'Cersei' if only to be a pain, but instead just grunts, and snakes a hand into Loras's breeches.
"Quiet now, Ser," Jaime murmurs when he hears Loras's breath catch. "We wouldn't want you to disturb the king."
Tommen - his son - is on the other side of the door they're meant to be guarding, like as not playing with his litter of fuzzy little beasts rather than sleeping. Jaime feels oddly detached from this idea. He knows the boy is his, knows it with his head, knows it every time he looks at him, but it never quite feels real. Like, maybe he's thinking someone else's thoughts, living someone else's life. Maybe someone else has been fucking his sister for all these years.
"I know how to be quiet," Loras hisses, as Jaime's hand wraps around him, cupping him hot and hard in the press of his good hand. Jaime's heard enough stories from men serving in Renly's garrison to not really believe him.
They move like that for a bit, not quite kissing, but breathing hard, wisps of warm air gliding across one another's lips, across Jaime's quickly re-growing stubble.
"You're not doing it right," Loras tells him, after a few moments, and Jaime can hear the amusement in his voice, only vaguely masked by arousal.
"I think I know how to - " he begins, but really, does he? He's fucked his way all over the Red Keep, in every corner and passage and open hallway, but he's never so much as stroked another man's cock. That on top of his thrice-damned left hand, and he's probably no better than a maiden, blushing and fumbling with her first lover.
Cersei had never blushed, and never fumbled.
That doesn't matter now, though, when Loras's hand wraps around his, grip not light, but neither as bruising nor obtrusive as Jaime might have expected it to be. "Slower," he whispers, breath ghosting along the curve of Jaime's jaw. "Not so rough, Kingslayer."
"I told you to hush, you mouthy, little - "
He's cut off by Loras's lips pressing against his own, and he tries not to smirk against them. The rebuke had mostly just been for show anyhow, and he does let up his grip, hand sliding against the cock in his hand rather than choking it.
"Ah, yes," Loras moans when Jaime pulls back, "that's - "
Loras does, biting into his lip, and maneuvering a hand beyond Jaime's armor and into his own breeches, squeezing, grip firm and clearly practiced. Jaime hates him a little bit for how good he is, but the rest of him is rather enjoying it.
They're grinding, thrusting into each other's hands by the end, trying to keep the groaning and the clanging of steel to a minimum in the quiet hall. Loras's breaths come quickly and his haughty face is flushed and wanting, and really, he is a beautiful boy, a sad boy, and Jaime can see the pain it takes to bite back the 'R-' when he tosses his head back and spills himself.
When Jaime comes, he moans an audible, "Cersei," into Loras's neck, mostly just to be an arse