Author's note: This is for a Beckett/Castle kink meme on LiveJournal, but it is so deliciously steamy that you should read it.

Music blaring. Drinks flowing. People bouncing and bumping. Couples grinding. This club is alive tonight.

Castle and Beckett spot the dirtbag they're suppose to be keeping an eye on. It's like a stakeout, minus the van and plus a crowd. Beckett doesn't anticipate making an arrest, but she's prepared if she has to. Never leaves home without her badge, gun, and cuffs. Castle still can't figure out where she stashes it all. He's especially curious during this undercover assignment because her dark red dress should be illegal. How can she hide anything when it barely covers her plump ass, has thin straps, and presses against her boobs so tight?

They've each had a drink and are now on the dance floor, blending in, selling their attraction to each other. If anyone paid attention to them, he/she would think they're going home with each other for a different kind of good time. But no one cares. No one's noticing them. Not even their dirtbag. They know that. They don't have to sell too much. But Castle can't keep his eyes off her...

Beckett is swaying her hips in front of him. Damn, that dress fits her good. She knows how to fit in at a club, not only from undercover work. She frequented clubs before she joined the 12th Precinct. Dancing and picking up guys were her fun. A part of her still feels that thrill whenever she's in a club, and tonight, not having to arrest the dirtbag, she lets her hair down, so to speak. She let herself have a drink, and now, she enjoys dancing. She enjoys so many bodies jostled together hopping to the electronic techno beats. She enjoys Castle being the body she has to be closest to.

Castle is not the best at dancing. He has been clubbing before and can bop around to a beat, but he doesn't have moves that she apparently does. He tries to remember to keep moving while staring at her hips. He loses his breath when she backs into him and slides herself down and up his body while reaching up and holding onto his shoulders. She steps away from him, still swinging, to glance at the dirtbag, and his eyes travel down her legs, which seem to be a mile long. Her black strappy heels match the sex appeal of her dress stunningly. How is he suppose to get through this night? She allowed them to have one drink (no more), and just now she pressed herself against him. She turns suddenly, and she appears to be having a great time. He grins at her to mask his bewilderment. Is this really work? She called him to meet her outside the precinct for this assignment. Is the assignment even real?

He reaches out to hold onto her waist, trying to keep up with her movements, when all he really wants to do is grab her ass and hold her tight against him. The way she slid down and up his body left him with a serious erection. He was already hard for her once she revealed her attire and then when she began moving to the music upon entering the club. But her dancing against him... His erection won't go away until he does something about it. And he wants her. He wants his hands everywhere on her, over and under her dress. He wants to shove his tongue in her mouth and wrestle with hers. He wants to make her gasp his name as he fingers her. But they're amongst people jammed in a club. He's helping with a case. He and Beckett aren't even a couple. He doesn't have the right to touch her anywhere he wants. But the attraction they have to one another is so strong... They don't need alcohol or being undercover to know that.

Beckett looks out to their dirtbag again and sighs in frustration. No suspicious activity. He's only there to have a good time with some women, it seems. And that's not enough. They need to catch him in the act. She turns around, leans in close to Castle, and says, "Doesn't look like anything's happening tonight." Her voice is hot in his ear, and he manages to reply, "Too bad." She moans, "Mmhmm," as she pulls away.

Subtlety. As always. A constant in their relationship.

He lets go of her but of course leaves his intense eyes on her. She runs her fingers through her hair and loses herself in the music. He eyes her up again, this time zeroing in on her breasts and all that skin above. He licks his lips and eyes her hungrily. Doesn't she know what she's doing to me? My God... I'm surprised a guy hasn't tried to snag her from me. Except...she's not really with me. Clearly, that doesn't matter. He'd be jealous anyway, and he'd do whatever he could to force a guy away. What would she think, though? He shakes his head. Why is his mind taking him there? She's here with him. Dancing with him. Enjoying herself with him.

She looks at him, stops moving, and glares at him staring at her chest. His desire clouds him, and it's written all over his gaze into her eyes. He lets it all pour out, and she doesn't know what to do, what to say. She's never seen this look before. This eye sex is deep, dark, passionate...until she abruptly breaks contact. And she keeps her distance between them. Clearly, she's not ready for anything more in their relationship, but Castle doesn't care about any of that tonight. He won't push her if she says 'no' to something, but he has to act on his urges.

She's turned around, her curvy back facing him. She has resumed dancing, and she figures his eyes are on her hips. He reaches out a hand to comb through her hair, tugging a little. He keeps up with the beat as he trails his hands down her sides and spins her to him. She grasps his arms, looking surprised, not sure what he'll do next.

He squeezes her waist, and his fingers run across her abdomen, feeling her body through her dress. Of course she feels amazing. His touch sets her on fire, and she instinctively wraps her arms loosely around his neck. They don't dare break eye contact as his hands wander around to her lower back, his fingertips skirting her hips. She gasps softly when his hands continue their journey and finally cup her ass. He presses her to him, and she gasps harshly at the feel of him hard against her. She can't be shocked. She knew what this dress would do to him. And now she can't complain about his actions. She likes the attention he gives her. Oh, yes, she does.

Castle grinds his hips into her, wanting so badly to be someplace else with her, to hike up that dress and just fuck her senseless. One of his hands slides down to the hem of her dress, dipping a couple fingers underneath and hiking the dress up just an inch while pressing into her thigh. Her bare skin feels even better. She breathes heavily, his hands and erection obviously having an affect on her. She somehow remembers to keep moving as she glances at his hand working its way up her side. He brushes the side of her breast, and she can't hold back the soft moan that escapes her. She closes her eyes as his hand eases down to her lower back. She reopens them when he suddenly pushes her thighs apart with his knee, keeping his thigh between them. He urges her to grind into him with his hands, desperately wanting to know if she's just as aroused as he is.

Beckett's mind guides her quickly through all the thoughts of how wrong this is, but she's enjoying this night with him so much. She does what he wants and develops a rhythm in sync with the pounding music. She secures her hold on him as she thrusts herself against his thigh. She is definitely hot for him. The moment she saw him in his blue-collared shirt, she wanted to rip it off him. Her panties have been soaked all night, especially while driving his Ferrari when he was eye-fucking her legs. Sure, she glared at him and threatened bodily harm, but nothing could keep his eyes off her permanently. Not even a yank on his ear. Now, he has forced her the chance to get off, and she lets him have control.

She speeds up, his thigh hitting her hot spot just right. Mmmm, it feels so damn good! Small vibrations from the dance floor help too. She starts panting, and his fingertips push into her ass firmly. "Fuck," she whispers loudly, feeling herself close to falling apart on him. It's exciting him even more to see that she is indeed quite turned on and is riding his leg, wanting to reach ecstasy. The way her thighs grip him feels unbelievable. He's always admired her thighs, and now, she's using those muscles to hold herself up and on him. He didn't think it was possible to get any harder, but it is. He needs to get off too, but surely, that will happen later. Alone. Being without her won't bother him like usual because he'll have the image of her coming in his mind. Oh yeah.

She whispers in his ear, "Castle," as her inner walls tighten.

He nips at her earlobe and demands huskily, "Come for me, Beckett."

"Yes. Yes... Oh fuck yeah!" She grips his shoulders and convulses wildly while coming on his thigh. His pants now have a large wet area, and her panties are definitely ruined. She's gasping strenuously. My God, that really just happened. Fuck! He's watching her intensely, amazed at how even more gorgeous she is when she's climaxing. She looks at him with glazed eyes while catching her breath. He keeps his thigh between her for her to rest on it.

She fights to regain the ability to stand. Once she can, he straightens his leg and slips his hands off her. They're still standing close together. She feels his hardness against her, understanding there is still fierce desire residing in him. She rests her head on his shoulder for a moment before planting a soft kiss on his neck - an expression of gratitude. She steps back and grins at his stunned appearance. He swallows hard, committing her lips on his neck to memory. He figures he should grin back, and it's his classic smug face. She rolls her eyes at him and turns around, looking sideways to check on their dirtbag.

It turns out, she did have to make an arrest that night. Luckily, they had enough time to form a sneaky plan to catch the guy. Now, he's on his way back to the precinct with Ryan and Esposito, who will also interrogate him. She needs someone else to handle the case after the night she's had.

Beckett and Castle drive back to the precinct in silence. Neither are sure how to address this night, but both are pleased with it. His eyes can't help but linger on her legs again, even as they get out of the car. His heart is racing for her. He will never forget how she looked and felt as she orgasmed. He stands at the driver's door. She has told him he can go home since she's doing the same. She begins walking slowly to her vehicle.

He has to ask because he isn't sure what she's thinking. "Do you want to come back to my place tonight?" Poor choice of words, he knows.

She turns, walks back to him, and replies, "Castle, this wasn't a date."

"I know. I wasn't... I'm not sure how you're feeling right now. About tonight. About us."

"I think I need some time alone to think about it. Tonight did kinda feel like a date, though." She grabs his lapel and kisses his cheek. "And I had a really good time," she whispers in his ear.

She turns around and heads to her car, grinning, knowing he's watching with an open mouth. She adds an extra sway to her hips just for him. He is staring, and he almost doesn't hear her say, "Goodnight, Castle." He remembers to breathe and stutters, "Night, Beckett."

She feels sorry for not going back to the loft with him and helping him calm his sexual beast. That would be too much for her. She's not ready to spend the night with him. At the moment, she doesn't think so. Maybe she wouldn't have had to stay, but time alone seems necessary. Plus, there's the thought of him jacking off while imagining her. That puts a smile on her face as she changes out of her dress in her bedroom.

In his bedroom, he ponders taking a cold shower. But where's the fun in that? He's hard, and he has a fresh image of her to get him off. The best image he's ever had of her. And it works like a charm.

The next day at the precinct is normal. Until nighttime when the place is cleared out and it's time to head home.

He helps her with her jacket and begins walking to the elevator. She reaches out to clutch his hand to stop him. He turns back to her, and she lets go. She smiles, and her smoldering gaze is enough to knock him out of his socks. "Let's go clubbing tonight," she suggests softly, as if it's a normal thing to say to him.

But then she leans in close, maintaining eye contact, and says seductively, "So I can take care of you the way you took care of me." She winks at him, and he can't help but smirk.