Disclaimer: Castle doesn't belong to me in any way shape or form.

A/N: Blame Sav for this. It's pure smut. That's all I'm saying. Also included a definition of the title for those who might not know what it means. It seemed appropriate.

SPOILERS for 6x21! You've been warned.

Concupiscent
adj.
filled with strong sexual desire; lustful

Her fingers aren't moving fast enough to satisfy, a low growl rumbling out when she fumbles with one of the last few buttons. She needs the shirt off him. Needs his skin against hers. But she loses focus, her brain fogging over when his teeth sink into her lip and god, he tastes good. Better than just good. She's been wanting him, needing him and was more than halfway to horny before she even suggested strip poker. Better than yet another rematch of scrabble.

She finally frees him of the red fabric hiding his skin. Beautiful soft red that makes her want to take a bite out of him but it's not as soft or warm as the flesh beneath. She doesn't much care for him pulling away to shrug out of it, the way he leaves her lips tingling and her body swaying towards him. But it's a brief moment that's barely more than a blip before he launches, crashing into her, setting her off balance. A yelp escaping her lungs and their knees knocking roughly when her back hits the floor. It's cramped, takes some wiggling and rough curses from him before she has enough space to pull his mouth back to hers.

The warmth of his skin against her own is just oxygen to the low blaze in her blood. Heat spirals through her limbs, settles thickly between her thighs with the press of his hips against hers. More. She needs more and this is way better than scrabble. She can't stop it, the moan that slides from her tongue to his, the way she rocks up into him.

His hands, those beautiful glorious hands sliding over her, up her ribs, and she lifts to let them slip under her back. She knows where those fingers are going, wants it just as much as he does. His mouth breaking from hers with a wet smack, blue eyes opening to watch the reveal and she says nothing. She settles back, gaze heavy with arousal as her bra gets tossed aside without a thought.

The air is cool despite the inferno building in her loins. Her skin tightens, nipples hardening under his scrutiny, her fingers carding through his hair as he groans. She knows that sound, knows that he's helplessly aroused and before she can even smirk, his mouth is on her. Teeth and tongue scraping, tugging, soothing. She's a mess beneath him, rocking against him, arching, pushing her breasts further in his face and against his seeking mouth. More. More. More.

That's all she can think and all she hears over the pound of her own heart, the rush of air she sucks into her lungs. More. All in. She wants him all in and she isn't about to fold. She knows his plan as soon his mouth slides to her rib cage and she's quick to tug him back up, pulling at his ears until he lets her guide him back up. She doesn't explain, giving him nothing more than a quick smile before she lifts her pelvis, rolling to take control. Their positions reversed, forcing him to knock into the table, swallowing his complaint with a rough kiss as she straddles him.

Now. She needs him now.

He's hot and hard beneath her, pressing right where she wants him, his fingers already sneaking up her thighs, slipping beneath her panties. And when he slides them through her folds, she shudders.

"Beckett." He's the only man that can make her surname sound sinful, salacious, and downright dirty. Accusatory. He's accusing in the tone and she knows why, can feel the same slickness. He's the only one who can barely touch her, just drag the tips of his fingers against her and have her gasping, writhing, so close to climax.

Not yet. She can't let herself fall over the edge just yet. And it takes all of her control to jerk back from his hand instead of thrust into it and just let go. But somehow she pulls away, somehow she gets rid of her panties and when her hand wraps around him, the hard length in her palm, she realizes that she has no recollection of how she got them off.

She just knows they're gone, and he's panting. Doesn't matter. Nothing matters but the way he grips her hips as she takes him inside, slowly. Already rippling around him, knowing it won't take much. He lifts into it, sliding deeper, the first thrust and she almost grips the table, almost needs the extra support. The way he fills her, the pleasant ache of him being inside is enough to have her rocking, twisting her hips.

She takes and he lets her. He lets her have the lead. Holding her, hands gripping as he watches. She knows he loves this, loves the way she enjoys taking over, riding him for both their pleasures. His eyes drifting to her breasts, a palm coming up to mold over one and she's arching, head dropping back as the first lick of flames intensify in her loins.

She races for it, for the finish her body is aching for. Her hips shifting restlessly, rocking, twisting, faster, faster. The rough short jerks, the sloppy way she bounces as her muscles begin to lock. And she sobs out his name, begging for something, she doesn't even know what until he gives her nipple one last pinch and then drags his hand down between them, rubbing over her. She's gone. Flying. Coming hard, her whole body shaking with it as she tightens around him, straining until her limbs liquefy and her body slumps forward.

He manipulates her, holds her close as he pins her beneath him. He takes the control, she lets him. Pleasure still zipping through her, sharpening with every thrust, she whispers to him, tells him to just let go. Her hands sliding around to pull him in deeper, gripping his ass as he buries his face in her neck. His breath hot and his teeth stinging as he bites into her on a rough groan.

She tells him again.

"Let go, Castle." And he does.

He drops against her, a shudder going through him as he nudges her nose and she accepts the soft kiss that follows. Lazy lips. Heavy breathing. The taste of sweat. She pats his ass, her fingers tapping against something cool and smooth and she's smirking into their kiss, practically snorting as she pulls the card from his skin. She hasn't even caught her breath but as soon as she sees it, she's chuckling.

"Wha-"

"You had an ace on your ass." She doesn't know why it's so amusing, why she's giggling and pressing her mouth to his over and over. She doesn't even know how or when they'd knocked the cards from the table.

"I think I'll also have several bruises."

"Still better than Scrabble." She turns her face into the palm he presses to her cheek. "We both win."

And it's the twinkle in his baby blues that just confirms what she already knew. They're going to be doing this again. Probably sooner than later. Which is more than okay.

They stay, wrapped up in each other, bare of everything. Neither one moving more than a few inches. Content to just touch. Her fingers soothing up and down his spine, pressing against the spot in his lower back that she knows flares up and bothers him sometimes. All the time he spends writing, hunched over in his chair always has it aching and it's become almost second nature for her to just rub over it, massage in little circles. He steals another kiss, letting her taste her own name as he says it softly.

"Kate," he lets his lips rest on hers, she can feel every word. "this is hurting my knees."

And before she can stop herself, she's rolling, raising her hand to cover her mouth, trying to hide her amusement but the shake of her shoulders gives her away.

"I hear that happens with old age."

"Beckett." It's a warning. One she doesn't heed, instead she's already sliding out from under him, barely side stepping the arm he swipes at her to pull her back. She grapples for her clothes as he steps up behind her. She doesn't expect it, the way he grabs her, lifts her easily. "You've had your fun at my expense, several times in the last few days."

She has. And she's enjoyed it. Teasing him. She always loves teasing him. She knows the look on his face, the glint in his eyes, the way he smirks. She knows where this is headed. She's not disappointed when he heads for their room, her arms around his neck, not even making a fuss.

She'll let him win next time he gets the urge to play Scrabble. Maybe. Probably not. No, she'll kick his ass.