Chapter 4

(Both are painfully aware that they are currently in relationships with other people at the moment.)

This time, they only make it through four days.

Kate is not above admitting that she needs sex but she stubbornly refuses to let some chemicals and hormones dictate the amount of control she has over her own body.

It's never been a problem for her before but maybe it's because he's always around and in her personal space. She's been in his bed now and she knows just how strong his scent can be; everyday is just a little bit more torturous when she can smell him beside her, reminding her of how good it felt to have him surround her body, inside and out.

Castle's brain, being male, has never veered too far away from sex. Before having the actual experience, he's wasted many an hour thinking about Kate Beckett naked in various places and in numerous compromising positions. But, now that he's actually seen her naked, he doesn't have to imagine it. Now, he just sees her naked everywhere – which is a little inconvenient when they're discussing a dead body in the morgue with Lanie.

This time, though, he's noticing that he's not the only one having trouble concentrating. He knows Kate tries really hard to hide it but he's been observing her for the better part of two years and he knows the minutiae of her ticks and quirks better than she thinks he does. For instance, now, when he stands too close to her, she immediately jumps away. She deftly avoids touching him even when he's handing her a cup of coffee (more often then not, she asks him to set it down on her desk lest their fingers accidentally brush). And she avoids his gaze even when they've come to the same conclusion on a case and they're finishing each other's sentences as usual.

Then, on day four, she gets extremely cranky.

"Esposito!" she barks as she's getting off of the elevator, "How long does it take to get a suspect's financials? I assigned you that hours ago and you're just sitting there!"

Esposito looks at Ryan who just shrugs. Then, they both look to Castle who's leaning against Ryan's desk.

"Dude, what did you do to piss her off?" Esposito asks.

"What? Me? Nothing!" Castle has a feeling it's definitely something.

"You know that she takes it out on us whenever you two have a spat, right?" says Ryan.

"We did not have a spat."

"Are you sure about that, bro?"

"Ssh, ssh," whispers Ryan as Beckett walks towards them.

"Ryan," she crosses her arms, "Where are the cellphone records I asked for?"

"Just waiting for the tech team," he answers.

"I want them on my desk in an hour." She strides away before any of them can respond.

The boys look at Castle pointedly.

"Fine," Castle huffs, "I'll go talk to her."

.

He knows where to find her. Somehow, in the minutes that he's spent debating what to do, she's already changed into her workout clothes and is currently beating the shit out of a punching bag. There are two other officers there lifting weights and they stare at him as he walks across the mats towards her. She doesn't acknowledge him; his only indication that she's seen him at all is the brief flick of her eyes in his direction.

"Ryan and Esposito think you're acting a little crazy today," he says, standing facing her but well out of range in case she decides to give the bag a swift kick and hit him in the process.

"And what? They sent you to investigate why?" she answers between punches.

"Well, they seem to think I had something to do with it."

She laughs but it's more sardonic than anything. "Tell them if they did their work, I wouldn't have to be such a hard-ass."

"So… it's not me?"

She shrugs. "You're always annoying, Castle."

"Only to you, Detective."

She lets him stand there for another couple of minutes before saying, "You can go now, you know."

He ignores her comment and scans the room. "Is this the only workout room?"

She looks momentarily confused but answers the harmless question. "Yes. Why?" then adds as an afterthought, "You thinking of purchasing a new set of equipment for us?"

He's not paying attention to her, merely noting that the room has cleared out since they've been talking. He shifts his eyes to the two doors at the back. "Do those change room doors lock? From the inside, I mean."

Kate stops moving, stilling the bag; she has a weary look on her face. "Yes," she finally answers.

Castle grins mischievously. Before she has time to react, he's grabbed her arm and pulled her towards the women's change room.

"Castle! What –"

"I have a better exercise for you, Detective."

He's surprised she's not resisting but when they've both made it through the door and she locks it behind her, he realises that she's caught on.

She's sweaty from her workout and her skin is hot when he touches her. He tries to peel her top off but she stops him.

"No," she says. She quickly unbuttons his jeans and then pushes him against the locker.

He gets it. She's in a hurry.

He turns them around and pushes her shorts and panties down at the same time. She's already doing that thing she does with her hands and he can barely concentrate on what he's doing.

"Wait," he says, surprised he can still think straight. "I don't have a –"

She shakes her head. "I'm on the –"

He slides into her before she finishes her sentence, completing it for her like he always does.

They're both so high-strung that it doesn't take much to get the release they had both so desperately needed.

.

"Feel better?" he asks after catching his breath. She's still shaky on her feet and his arm remains looped around her waist. Her head is resting on his shoulder, her breaths against his neck finally evening out before he feels her nod.

"You get really irritable when you haven't gotten any," his tone is humorous and seems to drag Kate back to a conscious realisation of what has just happened.

She extracts herself from his arms immediately, skirting around him and picking up her discarded pieces of clothing on her way to her locker. "I have to take a shower," she says and then scans him. "You should probably make yourself… presentable."

"Beckett. Wait."

She pauses in the middle of rifling through her gym bag for a towel. "What?"

"Uh, I don't know. Shouldn't we discuss these turn of events?"

"Castle, there's nothing to discuss. I needed sex. You needed sex. We're consenting adults. That's all this is."

"Yeah, except," he picks up his jeans off of the tiled floor, "We both have people in our lives who are supposed to meet that need. So, clearly, this isn't about the mind-blowing sex though, I have to admit, it's a nice bonus."

"Maybe you're just that good." She says this with a smirk but he imagines it's to hide from her uncertainty.

"I am that good." He tries to keep the tone light so she doesn't run away. "But, we both know this –"

"Castle!" she interrupts, "Let's just – just drop this, okay?"

"For now? Or until the next time you need a little pick-me-up?"

"Hey, you're the one who dragged me in here."

"Dragged?" he stretches out the word. "You were more than a willing participant."

"Don't tell me you haven't been thinking about this too, ever since that night."

Castle is sitting on a bench now, putting on his shoes. "I'm not denying anything. In fact, I'll fully admit that I've been thinking about you, naked and in between my sheets, letting me play out all sorts of dirty fantasies." The flush returns to Kate's face at his words. Now that he's gotten her attention, he continues seriously, "I've just been debating what to do about Gina. I mean, the first time, I thought it was a one-time thing but –" he gestures between them, "- if this is going to continue on then –"

"No," she interrupts him again. "This is it. You can do whatever you want about Gina but you and me, we're done. It was just sex, okay? Nothing else."

A/N: Okay, so I've started getting a little concerned about characterization. I mean, the show hasn't really shown this side of either of them so I'm just trying my best to extrapolate. Ideas? Comments? Suggestions? (You guys have been really awesome with your reviews so far!)