A/N: Set in the beginning of season 5.
She's sprawled out on the short green grass in his backyard the first time he realizes it. Her big black sunglasses are perched on her nose as she lays out like a starfish in her shorts and a tank top, looking like she's without a care and it hits him all at once that she looks happy. She's missing work and she's out here, in the Hamptons, alone with him and there's not a single worry line creasing the perfect skin of her face. A grin lights his own features as he takes her in, all bronze skin and lanky limbs, soaking in the last rays of summer.
"Get out of my sun, Castle," she says, startling his eyes up from the way they had been meandering across her bare knees. He can't see behind her glasses, but she sounds like she's not even looking at him.
"You're bossy on vacation."
"You're in my sun."
"There's a beach twenty feet away, why are you laying in the grass in all of your clothes?"
She only shrugs, taking a deep breath in as he watches her chest rise and fall. They'd only arrived twenty minutes ago and he's already captivated with this side of her. Moving out of her sun, Castle kneels down in the grass himself, plopping down as ungracefully as possible until his elbow is poking into her side.
"Seriously," she groans, and he can't help the smile that splits his lips as she pushes her sunglasses up her forehead to look at him.
"Do you want me to go grab your bathing suit for you? Much better for sunbathing." He leans in to drop a kiss on her cheek as his fingers sneak under the hem of her shirt, spreading across her warm abdomen, feels it jump under his touch. It still amazes him even after all these weeks the way she reacts to him, how a brush of his fingers or his mouth can make her come undone. It makes him shiver to even think about it, especially when she turns her head far enough to catch his mouth, sliding her tongue lazily against his. They both groan into it, her rolling onto her side and into him as his palm slides from her stomach to her side, gripping her hip as he helps turn her until she's all tucked against him, warm and squirming. "Or we could just birthday suit it if you want," he whispers against her ear as he slides a thigh between hers, but then she's groaning and pushing up and off of him, casting a long shadow as she stands over him.
"Stop trying to get me naked."
"Never," he swears as she starts walking backward toward the house, kicking out a foot to try and snag her ankle, only just missing as she dances from bare foot to bare foot, smiling triumphantly.
"Maybe I'll let you tie my bikini strings." Her grin is saucy as she finally reaches the back door, and he's up off the grass at a speed he hasn't known since his younger days, chasing after her as she darts up the stairs and out of sight.
"You brought a bikini?!"
"Don't crash the boat castle," she says, shooting out a bare arm to steady herself on the seat she's sprawled across as he hits a wave hard, jostling them both. She was not kidding about the bikini she brought with her, a dark blue strappy thing that covers her everywhere essential and exactly nowhere else. They had barely made it out of the house.
"Sorry," he mumbles, righting the wheel as they smoothly cut through the water, on their way back to the mooring just offshore from his house. "There's just so much of you and you're so…just…you're really – "
"Wordless, writer boy?" he can see her smirking, watches her puff her chest up a little bit, let her leg fall open just a touch more. Slowly torture him, basically.
"I have plenty of words for you: hot, half naked, beautiful, gorgeous, stunning, radiant – "
She makes a gagging noise, tipping her head back so she can see him. "I think I'm gonna be sea sick."
"I bet you're even a cute puker."
"Castle." Her head falls back to her seat but he can see her shoulders shaking with mirth. She's sitting on his boat, in her bikini, laughing at him.
"Come here," he blurts out, wishing he had someone else to drive his boat so he wasn't stuck gazing longingly at the sunbathing detective in front of him.
"I want to be touching you and you're too far away."
She pretends to think about it for a second. "Mm, no I'm comfy."
"Beckett," he whines, holding the wheel with one hand as he takes a step toward her, making the boat list to the side.
"Castle!" She's sitting up then, finally, and he can just reach her enough to snag one of her wrists in his grip, tugging her toward him.
She shuffles grudgingly, huffing as he presses his face into her toasty warm neck. "Mmm, you feel good," he says, slowing the boat down so they're barely moving. The brush of his tongue on her neck makes her shiver under him, she tastes like salt and sunshine, so much skin just his for the taking. Her reluctant façade melts away the second his mouth is on her, one of her hands coming up to slide into the back of his hair, holding his lips to her skin.
"Park this boat and you can touch me all you want," she breathes into his ear, letting her bare stomach brush against his fingertips and the front of his tshirt.
He groans loudly at her words, biting down on the soft tendon connecting her neck to her shoulder, making her arch into him.
"Help me drive."
"Help you drive – " she starts to say, but then he's sitting back down in his captain's chair, pulling her into his lap. She straddles him easily, the only way to sit without falling.
"You're so good at driving." His mouth lands on her shoulder as he presses the throttle harder, speeding the boat up and making her rock into him as they both groan.
Her hand snakes between them, pressing itself underneath the hem of his tshirt, sliding her palm against his bare skin. "I'm going to remind you of this the next time you're whining about riding shotgun." The point of her tongue drags across his ear as she maneuvers her way under the waistband of his bathing suit shorts, wrapping her fingers around him with zero pretense. "Did you know I'm really, really good at driving stick, Castle?"
His vision goes hazy as she touches him, all lazy and unrushed, a direct contrast to the heavy, choking need zipping through his blood. The fingers of his right hand close tightly against the steering wheel, trying to hold the boat steady as he finally catches sight of his house in the distance. Almost there almost there he chants to himself as she gives him a tug and then lets him go. He's about to whine out a whyyy, but then she's sliding both hands over his shoulders to get a grip on the back of his seat so she can grind herself against his crotch. Oh.
She lets out a breathy sigh as her hips roll against him, and it's all he can do to keep the boat on a steady path. Kate Beckett is sitting in his lap, rubbing herself against him because she's turned on, by him and he just can't believe any of it is even happening.
He lets her move with just a hand on her lower back until he's finally in range of the mooring, shutting off the boat with a flick of his wrist as he finally lets his right hand bury itself in her hair to pull her to him for a kiss. She groans into it with a wide open mouth, tongue sliding against his fluidly. She's so warm and moving and on him and here and he just wants to beach his boat so he can get her up and into the house and his bed as quickly as possible.
"Hey," he says softly, voice all gravel as he pulls her head back to make eye contact with her. She's still shifting rhythmically in his lap, lids hooded and he finds that he can't actually bring himself to stop her. One of his hands brackets her waist as his nose brushes hers, the fingers of the other tucking a stray hair behind her ear. "Do you want some help before we head in?" He lets his fingers trail lightly across her stomach to play at the elastic in her bikini bottom, tips just barely slipping under.
She groans, biting her lip, seriously considering, he thinks.
"I want you," she whispers, letting her lips barely brush over his, a sharing of breath more than a kiss.
He starts to slide his hand farther down, but she catches him at the wrist and scoots herself back and off of his lap, leaning forward just enough to put her mouth by his ear and her cleavage directly in his line of sight.
"Tie up the boat."
Their swim to the shore is quick, but not quick enough, and they both barrel their way up the slight slope in his backyard until they finally reach the sliding doors leading inside. Her skin is slippery and cool as he presses her against the glass from behind, his sodden bathing suit leaving absolutely no doubt to how much he wants her. The door finally slides open after she fumbles with it for an extended moment, and they don't even bother to towel off as they head straight for the stairs, clutching the banisters like children so they don't slip.
The second they finally make it to his bedroom, the doors opened wide, afternoon sunshine spilling in through the ceiling high windows, his hands are on her bathing suit ties, tugging until the material falls from around her torso and to the floor. Her bare back is tan and glistening with water droplets, and the muscles there tense under his mouth when he presses it to her shoulder blade. Goosebumps scatter at his touch as he slides an arm around her middle, holding her to his chest as she steps out of her bottoms.
"Take your suit off," she moans as the font of her thighs bump against the bed. He steps out of them as he nudges the backs of her knees, encourages her to climb up onto the bed, which she does with all those long graceful limbs of hers. He's right behind her in a second, on his knees and up against her back, sweeping her wet hair to the side so he can get at her neck.
A frustrated groan rumbles up and out of her as his fingers skim down her stomach, on a path straight for where she's warm and wet for him, but he must be going too slowly because she threads her fingers through his and yanks it down to where she wants it.
"Stop teasing, Castle."
He shivers at how desperate she sounds, how much she wants this, him touching her now.
"What do you want?" he husks into her ear, forcing their linked fingers along her upper thigh instead of anywhere else.
Her head tips back against his shoulder, and he can hear her squeezing her eyes shut. "Come on, you know what I want." The grind of her ass against him makes him start for a moment, but he's in the mood to play with her. They are on vacation after all.
"I will," his lips close over her neck, sucking lightly as he lets his fingers trail lightly back up her thigh and swirl around her belly button. "But I want to know everything that drives you crazy," he confesses into her ear.
"You drive me crazy." She's going for exasperated, but her body betrays her, truth leaking through.
"I can tell."
"Ugh, don't get cocky Castle, it's not – "
She gasps when he unexpectedly slides his hand downward, finally touching her.
"Fingers or mouth?"
"Which do you like better, here, fingers or mouth?"
"I don't…" she gasps as he starts rubbing circles. "It depends."
"My fingers or my mouth?"
She whines out his name but then finally answers him on a shaky exhale. "Your mouth."
He can't help grinning against her neck, that part of him that wants to do nothing but please her flaring to life. He moves his slick fingers to her hip then, turning her and pushing her down on the mattress, gripping her thighs in his palms.
"No Castle," she says haltingly as her hips arch up of their own accord, his mouth leaving wet, hot trails down her stomach. He can smell her and all he wants to do is taste her. He keeps going though, caught in a haze until she's tugging sharply on his hair. "Later Castle, later. Please, I just want you, just you."
He bites at her thigh then, once, her knees almost closing around his head at the sharp sensation, but then he's pulling her all the way under him, hissing at the way she immediately wraps her legs around his waist. They're completely backward on his bed, tan bodies against stark white sheets, sunshine glinting off of every surface when he finally presses into her, rolling his hips tightly as she rises to meet him, hands skimming their way along his sides as she bites back a groan.
"Everything about you makes me crazy," he whispers fiercely into her collarbone, hips going and going and going. He can't stop and she's only fueling his fire, nails tattooing crescents on his back as they rock together, completely out of control.
He thinks it's only a matter of seconds then, when she starts swearing out a string of yes yes yes's and hooks her leg just a little bit higher on his hip and then she's all tight and hot and bowing into him, his name on her lips and his body inside of her and oh oh oh he doesn't know where her orgasm stops and his begins because he's on fire enough for the both of them and neither can stop moving.
She's still panting when he finally rolls off of her just enough to shift his crushing weight, one of his legs still draped between hers as she grinds against the side of his hip a little bit, still finishing. Or he thinks she's finishing anyway, until she shoves at him, cheeks entirely too pink as she straddles his hip and keeps going.
"Are you…" he starts, but then she leans down and kisses him, hips rolling, and it must be good for her, exactly the right spot because he feels her second orgasm sweeping through her as it starts, catching her by surprise, he can tell because she doesn't have enough time to school her face or catch herself or even do anything but open her mouth slack against his as he lets her drape completely over him, taking taking taking everything she wants, everything she needs until a broken sob bursts from her chest and she collapses, finally still.
His hands trail lightly up and down her back as he feels her breathing start to even out, and then he just can't help himself. "So," he starts, moving the hair away from her ear so she can hear him. "Is that a thing that makes you crazy?"
He feels her laugh against him, finally looking up at him from her perch on his chest, shrugging as she worries her bottom lip between her teeth. "I wasn't done."
If he wasn't sure of it before, this little weekend escape to the Hamptons has confirmed it – she's going to be the death of him.
It's dark when Castle finally wakes up again, his empty, rumbling stomach demanding to be fed. Beckett's sprawled out on her stomach beside him, sheet barely covering her, face smashed in a pillow. She looks comfortable and satisfied. He can't help the cocky smile, the swagger as he slips out of bed, the reality of just how lucky he is settling somewhere heavy in his chest. He did this, he gets to do this, with her, the two of them together.
He lets the fingers of his right hand trail lightly down her bare calf, peeking out from beneath the sheet just because he needs to be touching her, and it hits him all at once that he's never going to be able to get over her. It was never an option, truly, no matter how many times he tried to tell himself he'd be okay with just her friendship, her partnership, but now, standing in the darkness of his bedroom, their bedroom, he knows it for the lie it was. There was never any going back, never a path going forward without her that didn't feel inherently wrong.
She's here now, though, under his fingertips, warm and real and in it with him, he's fairly sure, for the long haul. She told him once she's a 'one and done' kind of girl, and he believed her then, as he believes her now.
His thoughts run away with him as he stands there, watching the moonlight play along the blonde highlights in her hair, wink across her nose, so many nights like this to come. Summers alone, with family, holiday parties, little feet on his hardwood floors. The enormity of it chokes him, roots him to the spot until her voice coaxes him out of it, the only light he needs in the darkness.
"Castle?" she whispers, voice clogged with sleep as she scrapes the hair away from her face and props herself up on an elbow.
Had his thoughts been loud enough to wake her?
"Hey," he says warmly, the affection in his tone deep enough to surprise even him. She smiles at it though, soaks it in.
"What time is it?"
"Eight. I was just going to make something to eat, you hungry?"
Her stomach rumbles almost as if on cue and she laughs, flopping over onto her back.
He's already out of bed, should just turn and head downstairs, get them some food so they don't waste away, but he's drawn back to her inexplicably, just needs to be close to her for one more moment, so he kneels down on the bed, crawling back over her body to pull a gentle kiss from her lips.
"Mm, what was that for?" she whispers, palm flat on his bare chest.
"Just glad you're here." It's a lot, he knows, what he's carefully not saying, but she gets it anyway.
"Not going anywhere," she lets float into his mouth on the air between them, a promise.
They kiss again, exactly once before he breaks the moment, biting her lip playfully.
"Sorry, starving," he says as he pushes himself back to the floor, watches her rub her lip and then suck it into her mouth.
"Bring me some coffee too," she yells as he makes his way down the stairs, smiling like an idiot.
A happy, happy idiot.