A/N: Thank you so much for your input on that last chapter! We'll move on to the beginning of Season 6 now, so this chapter finds Kate still with the AG's office, but we'll get her back to NYC in the next one I should think. Sorry I haven't had time to respond to reviews on the last couple of chapters, I've been on tour and figured you guys wanted me to spend what little free time I have on writing these chapters! I do appreciate each and every follow, fave, retweet, and review more than I could possibly say. You are all rockstars.

WARNING: RATED M.

Fantasy Fridays
Chapter Thirteen: Swing Set

Castle surfaces at noon.

He stumbles into the kitchen and heads straight for the coffee machine, wincing as the sunlight streams into Beckett's tiny apartment. He puts extra milk in to cool his coffee down and drinks it all in four huge glugs.

He's been out of the hospital for three days and he's pretty much slept through all of them. The doctors had warned him that the fatigue would stick around for a week or so, but he didn't realize how debilitating it would be. The only upside to getting poisoned is that he's been able to stay in Washington. He cancelled his plans for the week and settled into Kate's apartment. It's been wonderful to have her beside him at night. And in the early hours of the morning, when he surfaces from the crush of sleep, he gets to wake up to her smile. Soft pity still lingers in her eyes, even though it wasn't her fault that he got himself mixed up in her case.

Just before dawn this morning, he'd heard her moving through the apartment, but the white noise of her shower had lulled him back to sleep. She'd brought a mug of coffee to his bedside table, but he couldn't even raise his arms to take a sip.

She'd leaned over, brushed his hair from his forehead just like she had in the hospital, and he'd opened his eyes even though it felt like lifting weights.

"I'll be back at six tonight, unless we catch a case," Kate had whispered. She still uses cop lingo with him - it doesn't feel right when she uses the more formal AG vocabulary.

"K. Love you," he'd mumbled.

"I love you too, Rick."

Castle catches himself staring into space and programs the coffee maker for another mug, double shot. There's a note from Kate next to it, call me if you need anything, and he rubs a hand over his face. She's still blaming herself, and she's still worried. She's treating him like something fragile, and every time she looks at him her eyes spill over with adoration and concern. He likes it, but the novelty of being Sleeping Beauty is wearing off. He's never felt guilty about milking the attention before, but with Kate it's different. He's not being a very useful partner. She's being patient, but it won't be long before he starts to annoy her. Annoying her at work is one thing - it's so fun to get her riled up - but he doesn't want to actually annoy her.

And something's been missing since he got poisoned - something he's not willing to give up just yet.

She hasn't looked at him like a sex god. Not since he surprised her and fucked her senseless against the wall of her bathroom. And he wants to be Kate Beckett's sex god for as long as he can. He's under no delusion that they'll be insatiable forever, but he wants to get a good ten years into their marriage before they start slowing down.

He's just so damn tired. The thought of an energetic round of thrusting actually makes him yawn.

And then, halfway through his second cup of coffee, inspiration strikes.

"Castle?"

Kate drops her keys on the counter. She barely recognizes the kitchen. Most of the boxes are gone, and some of her stuff is arranged neatly on the countertop. She opens a cupboard and sees her dishes stacked neatly inside.

There's a thick candle burning by the coffee maker, and her pulse jumps. He's been awake today, for at least a few hours if he managed to unpack some boxes. The candle hasn't burned down much, so he might even be awake now. It'd make a nice change. She's not annoyed - she wants him to take his time recovering - but she'd also like to have dinner with her fiancé instead of the television.

She pushes the door to her bedroom open and her smile slips. He's in bed, in just his flannel PJ pants. Sleeping.

But there are more candles, everywhere, on the floor because she doesn't have a whole lot of furniture, on the single bedside table, even on the windowsill.

She perches on the side of the bed and leans over to kiss him, a soft brush of her lips over his, and she's about to rise to change out of her work clothes when his hand shoots up and weaves through her hair, pulling her back down for another kiss.

He's obviously awake, because the kiss isn't the lazy, tender kind she gets when he's coming around.

She opens her eyes to find his blue ones gazing at her.

"Faked you out," he says, and there's not a trace of sleep in his voice.

"How you feeling?"

"A little better. I did have an afternoon nap, but not before I got some chores done."

"I saw. Kitchen looks great."

"And I even got you a present," he says.

"A present? What for?"

"You should know by now that I don't need reasons to get you presents."

"Castle - "

"Yes, I know, I know. But this one is actually a present for both of us."

He reaches over the side of the bed and brings up a lumpy parcel of newspaper.

"Nice wrapping paper."

"We do what we can." He'd considered buying the wrapping paper covered in tiny cartoon penises from the same online store that sold him the gift, but somehow managed to resist.

Kate sets the parcel on her lap, looking so purely delighted for a moment that it makes his heart swell.

She slides her finger under the tape and peels back the newspaper until she's holding a tangled pile of nylon straps. Two pieces of mysterious metal hardware clink together, and her eyebrows knit as she studies the gift.

"I've got a sneaking suspicion that this is for our personal recreational use, but I'm not sure how it works," she says, turning it over in her hands.

Castle points to the ceiling and her eyes flick up.

There's a very serious metal hook in her ceiling that wasn't there this morning.

"Hang this up there," Castle says, finding one of the rings attached to the pile of straps and pressing it into Kate's hand.

She raises an eyebrow but gets to her feet, nimble and balanced on the soft mattress. She's in her very well tailored work pants, and he can't resist smoothing his hands over the backs of her knees as she hangs up their new toy.

It's more obvious what it is now, a collection of straps that hang from the ceiling and end in padded loops.

Maybe another girl would be shocked, offended even, but Beckett's eyes flash with dangerous anticipation when she looks down at Castle.

"How did you know I wanted one of these?"

Castle grins widely, because he didn't know, not exactly. But her track record has shown that she's very amenable when it comes to trying new things and bringing accessories into the bedroom.

"Well, fiancé of mine, I figured since we can't really have one in the loft, we could have one here. Besides - I know I haven't exactly been energetic in bed recently, and I wanted to make sure you were still happy and apparently these are really good for taking a bit of strain off and - "

"Castle?"

"Mmm?"

"Shut up."

She reaches down, loops her fingers through his hair, and pulls his face into her crotch.

Her zipper is hard against his nose, but his lips are pressed to the plush mound of skin underneath the fabric of her dress pants, and she smells amazing. Musky and warm. He reaches around her to grab her ass, kneading into her as he gives her a playful nip with his teeth.

He looks up and she's undone half the buttons of her shirt, so he undoes her pants and starts tugging them down her legs.

She's impatient tonight, whipping off her bra with no preamble, batting him away when he tries to stroke her clit through her underwear just so she can shove them down as well.

"What's the rush, babe?" he asks innocently from between her legs, locking her fingers through his as he takes his first long, leisurely lick of her. "Oh," he says when he finds her dripping. "You couldn't have got this ready in just the last two minutes."

"Mmm," she purrs. "I may or may not have been thinking about your cock on my way home. I was going to ambush you with a stealth blow job, and I think I would have ridden you even if you hadn't woken up by the time I got you hard."

"Jesus, Kate." She's so filthy sometimes. He loves it when she turns all cop on him, no shame, not flowery words, just a simple statement of what she wants.

She lets him lick her, suckle at the bud of her clit until her legs tremble.

"Get in that thing," he husks as he brings one hand to the tent he's pitched in his pajama bottoms with his erection.

She's dizzy with lust as she tries to work out the loops, finally figuring out that she has to step through two with each leg. Castle helps her tug two straps up to her thighs.

"Too tight?"

"Tight, but good tight," she manages, a little turned on just by the black bands strapped around her. Two more straps fit around her ankles, and Castle takes a moment to appreciate the fine structure of her lower legs. He's always been a sucker for them, she's known that almost as long as she's known him. It's made wearing dresses a lot more fun.

Kate grabs the final two loops, wrapping them around her wrists before grabbing the rubber handholds.

"I think I'm in."

"Isn't that my line?" Castle quips.

"Har har. Take my weight, babe."

He settles his hands on her waist and she sinks down until she's on her haunches. She feels her weight settle most on the bands around her thighs, and in an instant she feels herself spread open. She feels wanton, and so good already. She takes more weight on her hands and slides her feet over the surface of the mattress until she's almost doing the splits.

"Well, what are you waiting for?" she says. "Get under me."

"Yes ma'am."

Castle wriggles down until his body is under hers. He shoves his pants down to his ankles, freeing his bouncing erection. When he's settled, he looks up at the exquisite seductress above him and his mouth goes dry.

"Holy fuck, Kate, I wish you could see what you look like right now." He's going to have to take pictures, but not this first time. This time he just wants to feel.

Kate lowers herself down to him. She rubs her wetness over one of his thighs, pressing his erection flat onto his stomach as she glides over the length of him. She does it two more times, her eyes closed in bliss as she feels the velvet hardness pass under her, parting her, until he's glossy with her desire.

And then she takes her weight completely off the mattress - she's always been able to do more pull-ups than him - and when he looks at her feet they're in the air as well and he nearly faints with the kinky hotness of it all. She's got perfect aim, doesn't even need her hands for this. She positions herself right on top of his cock where it's straining straight for the ceiling.

She lets her arms go. She drops down onto him, every straining inch of him, in one harsh crash with every pound of force in her body. The shock of it sends a dry shiver right down to his balls. She's hot and tight and wet around him, and she pulls up again, drops again. Someone moans.

"Fuck, Castle, this was a brilliant idea."

"Spin."

"What?" Her eyes find his, stormy and hooded.

"Spin."

He maneuvers her with his own hands, using her thighs to spin her 360 degrees on his cock, and the sensation is better than any he's ever known.

"So good, Kate," he grinds out.

"Me too," she pants, as she does another lift and drop onto him. "Fuck. For me too."

He lets her tease herself, work herself over him, lets her find the angle that has the curve of his cock pressing right against that rough spot that has her shaking, and then he pinches her clit, presses and rubs fast circles into it that have her going limp in the straps. She looks like something out of Lady Irena's lair, and he kicks himself for not buying some ridiculous strappy black lingerie to complete the look. Maybe some Mistress Red lipstick. But he can't complain, and there's always a next time.

Somehow, he holds on through her first two orgasms. Nearly an hour later, she's on her hands and knees with her ass lifted in the air by the straps of the swing. He's got his hands on her hips as he guides her on and off his cock. It's strange - he's not pounding into her but she's pounding onto him, so hard that his balls slap against her clit. She cries out, her walls tightening around him and he can't hold out a second longer. He grabs the straps above her body for balance as she knocks his world off kilter as his own orgasm rips through him.

"I like how we're taking our thing for swing sets to the next level," she sighs after he's peeled the straps from her limbs and helped her down to the bed.

"That hadn't even occurred to me, but it's perfect."

"You know we're going to have to get one of these for the loft. I saw once that they make little fake smoke detector covers to hide the hook in the ceiling."

Castle raises his eyebrow even as he does a little happy dance in his head.

He's totally getting them a swing for their loft. And a proper one with a big frame and everything for the Hamptons where they can lock it away in one of the spare rooms.

And yeah. He's never going to be able to look at their swing set in the park in quite the same way ever again.