A/N: The first chapter is M rated! The rating will change to T in the following chapters!
I would say this story is set after s8, Castle and Beckett are already married, but it isn't based on any specific season or episode.
Hope you enjoy! :))

"Mmm, it's so delicious," Kate Beckett had exclaimed with her mouth full of food.

They were in a small, cozy Italian restaurant, designed with softly toned woods.

The vibe of the old fashioned wine bar, and the soft, flickering candlelight at the middle of their rounded table made it a perfect place for a romantic evening to celebrate their third wedding anniversary.

Kate had a long and exhausting week, working on hard on a complicated case. Now that the case was finally solved and justice had been served, she couldn't wait to finally have some private time with his husband.

They both ordered a large pasta dish, coated with tomato sauce, and a bottle of their favorite red wine.

"Thanks for inviting me here, Castle." She added with a low, gentle voice after chewing and swallowing her meal, after taking a sip of her Sancerre.

"Always!" He replied with a soft voice, his lips curling up in a contented smile, his bright blue eyes shimmering like sapphire in the dim, flickering candle light.

"I'm glad you enjoy being here. Wasn't sure you would like this place." He then added on a breath, his voice barely louder than a whisper.

"Why?" She had inquired, furrowing her brow, twirling a long string of pasta along her fork. She kept twirling it until there were only a few, dangling ends, then she placed in into her mouth, the simple but delicious taste filling her insides.

"I don't know, I just... I know you would prefer to eat at more intimate places, " He had sighed, lowering his gaze, wrapping the fork tightly around his own spaghetti, loading up a few long strands on his fork as well.

"I know this restaurant seems pretty crowded right now, but-"

"It's okay Castle." She cut him off in a hushed, reassuring tone.

"I enjoy it wherever, as long as you are there with me." She asserted with a low, gentle voice, covering the back of his hand with her own, lacing her fingers with his.

Her action got him by surprise, his eyes immediately flickered up to meet hers.

For a moment too long he was just staring into her beautiful, gleaming eyes, completely stunned by her amazing presence.

No matter how many years had passed, Kate Beckett was still the most wonderful woman he had ever seen. Her honey brown hair was perfectly tied up in a bun, its loose curls shimmering gold in the dim lightning of the room. Her eyes were usually green like an emerald, but now in the dim, flickering candlelight the color of her eyes were more likely somewhere between hazel green and honey brown, it was hard to tell which one excatly.

She was wearing a simple, but elegant red dress, which was perfectly clinging to her slender frame. She was wonderful. Whatever she wore, she was always wonderful.

"Oh, God! You are beautiful Kate!" He blurted out without even thinking any further, unable to keep her eyes off of her.

"Thanks, Castle." She mumbled under her breath timidly, shying away from his gaze, trying to hide the blush on her cheeks.

She quickly collected herself by tucking a loose strand of hair behind her ear, then she lifted her eyes up again, slowly and tentatively leaning forward to press a kiss to his mouth.

She was about to brush her lips to his, when her eyes landed on a strange figure near to the front door. His face was covered, hidden behind a large, black hoodie. It was weird. So weird. His features were barely visible, but when their eyes met for only a brief moment, she felt like knowing him. He was was familiar. So familiar and yet, she couldn't place him anywhere. She had no idea who he could be.

"Do you know him?" Castle had asked, frowning, curiously following her gaze toward the weird guy.

"I'm... not sure." She mumbled hesitantly, frowning as well, still looking at the dark figure, who was now sitting at a small table at the corner of the restaurant, occasionally sparing a piercing glance at her.

"Does he make you uncomfortable? We can go if you want." He had suggested, gently brushing the back of her hand.

She didn't even notice their hands were still twined. Just a single touch, just a quick brush of fingertips and her insides were already tingling, the uncomfortable knots in her stomach slowly loosening.

"No, it's okay. We can stay." She insisted, flashing him a reassuring smile, averting her gaze back onto her plate still full of food.

In the following minutes they were eating in awkward silence, then Castle started talking about lighter topics to ease the tension.

She bursted out in hard laughs time to time, the sound of her carefree laugh caressing his ears like a soft melody. She wasn't drunk, no she was able to control herself despite the amount of red wine they had drank in the past few hours. She was just simply happy, carefree, enjoying the moment, enjoying their third wedding anniversary.

A cool breeze hit her face in a second they stepped out of the restaurant, the sudden shock of cold air making her entire body shiver.

Kate was wearing a thin coat only, the weather was still nice and sunny when they left home earlier, she didn't even consider bringing a warmer coat. The degrees were still positive, but the fall was slowly coming to an end, the frigid, late night November air reminding her at every step that winter is just around the corner.

The brisk autumn air made her nose wet, she had to blew it out with a tissue from her purse. After pocketing the tissue she squeezed the barely sensable coat tighter around her body, trying to cover the exposed, bare skin of her neck like it would help to keep her warm.

"Is it that cold for you?" Castle had asked, worry and concern mirroring in his voice.

"It's okay, we are almost at home I will make it, don't worry!" She lied, exhaling heavily at her ice cold, trembling hands. They were only a few blocks away from his loft, but she was already chilled to the bone, her entire body shivering, trembling like a leaf, she could barely feel her fingers.

"Jeez, you are freezing Kate, let me help you!" He insisted, draping his own coat around her shoulders without hesitation, without even asking, tugging her shaking frame into the cove of his body.

"Thanks." She mumbled, her voice shaky, trembling hard after each syllable. She snuggled closer into his embrace then, looping her arms around his waist.

Leaning into his side her body finally started warming up, the exposed skin of her bare shoulders slowly heated up under the warmth of his large coat.

Now that she wasn't freezing that much, she lifted her gaze up, observing the starlit sky for a moment too long. She then lowered her gaze back onto the sidewalk, watching some other pedestrians strolling on the dimly lit streets of New York.

She grew up in the city, she knew every street, every corner like the back of her hand, and she could never get tired of this amazing view, as the soft glow of the city lights illuminated the entire street, bathing them both with a golden light.

Resting her head against her shoulders she inhaled deeply through her nose, the chilly night air momentarily numbing her nostrils.

"Do you feel better now?" Castle had whispered, brushing a loose strand of hair behind her ears, making her entire body shiver with warm pleasure.

"Yeah, thanks." She nodded in a reply, a contented smile tugging at her lips.

"And once we get home, it's my turn to keep you warm, Castle." She then whispered into the shell of his ear, her low, gentle voice making his insides flutter.

"I will keep you warm in many different ways." She added on a breath, her numb, freezing fingers toying with the hem of his shirt.

"Oh, Katherine Beckett, I never thought you would be that kinky." He retorted, his husky voice an octave lower, teasing her the same way.

"See, I'm full of surprises." She bit back, smiling in contentment.

"Just wait til we get home, and -" He silenced her with his own mouth then, cupping her face in his large palms, unable to resist her any longer.

"Can't wait." He breathed into the bare skin of her neck when their lips aparted to get some fresh air, his mouth already missing hers. He then quickly pulled her in for another slow, long kiss, tasting the remnants of dinner on her parted lips.

When they finally crossed the treshold to his loft, Castle was unable to keep his hands off of her anymore.

After closing and locking the front door he pushed her to the wall instantly, kissing every inch of her skin, cupping her breasts through the think fabric of her dress. She moaned in response, burrying her fingers into his hair, her mouth hungrily searching his. When her lips found what they were looking for she fused her mouth with his, kissing him as fiercly as she could.

The loft was emty, Alexis was at a school trip for a few days, and Martha had other plans for the night as well, so without thinking any further he started undressing her right there in the kitchen. He quickly unzipped her dress with his nimble fingers, slid it down her legs, letting it fall onto the floor. She stepped out of her clothes without hesitation, her mouth still locked with his, her fingers desperarely searching for his belt. While she undid his belt and unbuttoned his pants he quickly got rid of her bra, unclapsing the white cotton with a quick sweep of his hand. He then slowly skimmed the tips of his fingers along her skin, tracing the lines of her exposed breasts.

She shivered at his touch, a wave of heat spreading through her ice cold body.

After he finally stepped off of his unbuttoned pants as well, she hooked her legs around his waist and laced her arms around his neck, hungrily kissing the skin of his bare shoulders. He cupped her ass in response, squeezing it firmly, holding her tight against his own body. He then hoisted her up into his arms without hesitation, taking fast steps toward the bedroom, kissing her cheeks, her neck, her breast, wherever he could, wherever his mouth landed.

Once they got into the bedroom he slowly, carefully lowered her down, easing her onto the mattress. Her entire body shivered when the naked skin of her back came in contact with the cold sheets beneath her, but she didn't care at all. She knew her yearning body will heat up in a matter of seconds beneath the work of his fingers.

After letting her sink into the mattress he quickly got rid of his own shirt and stepped out of his boxers.

He then crawled in bed too, kneeling above her, fusing his mouth with hers. She parted her own mouth in response, her tongue welcoming his in a fiery, passionate kiss.

Her fingers were digging deep into his hair, when his mouth abandoned hers, planting hot kisses onto her neck and shoulders. He then lowered his mouth down the corner of her left breast, his tongue hungrily licking the tender flesh above her sternum, eliciting a shiver down her spine and a low moan from her sligtly parted lips.

He knew every inch of her skin, every curve of her body, every single faded scar like the back of his hand, but he still took his time exploring her like it was their first night ever together.

He was about to trace his fingers along her lower body, leaving hot, ticking kisses on the naked skin of her belly, when his eyes landed on her white, lacy underwear, the only piece of material left between them. He slid it down her legs with such an ease, the soft caress of his fingers making her blood sizzle with anticipation.

Her legs were already parted, ready for him to enter her, ready for him to came home where he belongs, but he just kept teasing her over and over, skimming his fingers along the most sensitive parts of her body, stealing kisses here and there, eliciting a hot, burning shiver down her spine, accompained with loud moans from her mouth.

"I will make sure you never forget this night." He whispered into the bare skin of her neck, slowly crawling over her, pushing her deeper into the mattress, the weight of his warm body pressing hard against her naked breasts, heating up every inch of her bare skin.

"Oh, so are you punishing me now?" She panted heavily as he began teasing her, his lenght caressing her entrance in a cirling motion.

"Yes, I am." He rasped proudly with a knowing smirk, his eyes meeting hers.

"For what excatly?" She snapped back without even missing a beat, holding his gaze steadily, her hands slowly skimming down the lenght of his spine.

"For stealing my coat." He managed to get out on a strangled breath, slowly loosing his control over the hot brush of her fingertips.

"I didn't steal it, you gave it to me on your own, remember?!" She shot back teasingly, cupping his men parts with her free hand, squeezing it firmly.

"Uhm, I just wanted to be polite, you know." He wheezed into her skin, cupping her breast in response, tickling her already tightened nipples right on the spot where it always makes her loose control.

"Yeah sure, so you can punish me later, right?" She breathed out heavily, gasping for air, the work of his fingers slowly driving her crazy.

"Yes." He agreed, panting as well.

"Now you get what you deserve." He added on another strangled breath as his men parts were playing with her lower body, circling around the most sensitive part of her, eliciting an unexpected, loud moan from her mouth.

"And what would that be?" She heaved into the bare skin of his chest, gasping hard for air, slowly falling apart beneath the work of his body.

"Naked punishing." He blurted out on a harsh breath, grinning ear to ear, seemingly pleased with himself.

"So are you ready?"

"Yeah!" She replied faster than she wanted, spreading her legs wider to finally take him in, to finally feel him inside, but to her dismay, he didn't plunge in yet, just kept teasing her around her entrance over and over.

"Oh God, Castle! Just do it already!" She panted heavily, her entire body burning with anticipation, her body slightly rocking forward, yearning for him more than ever before.

"Never thought you would beg this hard to have sex with me, Beckett." He quipped in retort, breathing heavily into the naked skin of her shoulders, a satisfied smirk plastered all over his face.

"Shut up." She wheezed in response, still gasping hard for air, barely able to control herself.

"You can't resist my charm, can you?" He rasped, the hot puff of his laughter staining her naked skin, making her entire body shiver. He then planted his broad palms to her uncovered breasts, squeezed them slightly, just enough to elicit a loud whimper from her slightly parted lips.

Kate was now a moaning mess beneath the work of his fingers, her entire body wet and sweaty, squirming with want and need.

"Castle, please, can you just shut up, and-" She moaned eagerly and with that, he finally plunged in with a smooth, gentle thrust, closing all distance between them. All the words died on her tongue when his lenght finally came in contact with the right place between her legs. She cried out loud, eyes flickering up in pleasure, her body rocking forward instictively, her inner muscles clenching hard.

"Oh, God Castle," She panted into the bare skin of his neck, trying to muffle her cries.

"Is it too harsh?"

"No, it's okay. It's... fine." She managed to get out on a strangled breath, her body swaying forward, deep into his, matching the gentle, steady rhythm of his thrusts.

They fit together like the jagged pieces of puzzle, completing, filling each other.

"Faster, please... Oh, God Castle!" She gasped out loud, slowly loosing her self-control, digging her nails into the taut muscles at his back to hold onto something.

"Fas-ter, please," She kept begging, her breath catching harshly after each syllable due to the hot, burning pleasure slowly overtaking her entire body, spreading through her insides like a wildfire.

She then folded her legs higher at his waist, pleading him to slide further inside her.

He gave her what she wanted, fastened his thrust, cradled her yearning body in his arms like it's the most precious thing he ever held, but he was still careful, withdrew then glided back in slowly, gently, trying not to cause her any more pain.

Kate was almost at the edge, breaking apart on soft moans beneath the sway of his body.

Her hips were jerking forward after his every thrust, white-hot pleasure running up and down her spine.

Her vision slowly started fading as as his thrusts eventually became faster and sharper, her entire body slowly melted beneath him.

She felt herself carefree, flying somewhere above the clouds where nothing else matters just happiness.

Her mouth occasionally parted on low moans and whimpers until her vision completely faded, little white stars dancing before her eyes. Her control slowly faltered, she was unable to keep track of herself anymore, all she could feel beneath his thrusting, moving body was pleasure, desire and want.

When she came down from the clouds, from the endless sea of pleasure, she slowly opened her eyes, looking straight into his satisfied, delighted gaze.

Her own legs were still parted, slightly quivering, her body limp and sated, slick with sweat.

She didn't know how much time had passed, minutes or even hours since she passed out beneath the work of his body, but he was still kneeling above her, gazing down lovingly at her uncovered, sweat stained body.

"Staring's creepy, Castle." She mumbled, flashing him a weak smile.

"Sorry, I can't help it, you are beautiful when you sleep." He shot back teasingly, circling his thumb around her lower body in a slow, soothing motion, right on the spot where her muscles were already swollen.

She only hummed in response, squeezing her eyes shut, enjoying the work of his soft fingers for the second time in a row.

"Tonight was amazing, Castle." She muttered, opening her eyes once again, looking straight into his sky blues, which were now shimmering more like sapphire in the dim lightning of the room.

"Best anniversary ever." She then added on a breath, cupping his face in her palm, gently caressing the lenght of his cheekbones with her slim fingers.

"Yeah, I agree." He nodded with a contented, pleasant smile tugging at the corner of his lips.

"So does it mean," He began, tracing his fingertips along the curve of her left breast, eliciting a shiver down her spine.

"That you are ready for round two?" He inquired playfully, tickling the naked skin of her breast, circling his thumb along her tightened nipples just enough to tease her, just enough to drive her crazy.

She hummed in pleasure, her body slightly jerking forward, her toes curling up in excitement.

"Yeah, sure I am!" She breathed into his mouth with a sultry voice, quickly rolling him over, landing on top of him, her aching body oh, so ready and greedy for more.

Then it was all about the pleasure and fun again, they kept each other warm all night, just like they had promised.

On the next day she woke up sore, barely able to move her legs.

Kate was about to snuggle into the warm embrace of his body, but her dismay, the sheets and pillows next to her were cold and emty. Castle had probably woken up earlier, making her breakfast just like he always did. Sweet man, she had thought, smiling under her breath.

Sighing tiredly she then slowly untagled herself from her own sheets with her aching legs, her naked body already mourning the warmth of the bed.

She was about to get up and take a quick shower when a strong, disgusting smell hit her nostrils, suddenly making her all nauseous.

Kate rushed into the bathroom as fast as she could, still completely naked, kneeled over the toilet and heaved up the remnants of last night's dinner in a matter of seconds.

After emtying her stomach and collecting herself she leaned heavily against the wall, contemplating her options.

Can it be pregnancy? She wondered still panting, gasping for air, wiping the cold sweat away from her face.

Well, not because of last night of course, she knew it would be to early to notice yet, but they did ...those kind of activities in bed more than often lately, sometimes not even wearing a protection, so... this could be it, right?

And if it isn't pregnancy, then what else would it be? She wondered, still breathing a bit harshly, the bare skin of her back still heavily pressed against the wall, the ice cold bathroom tile making her entire body shiver.

A/N: So this is the first part of my very first multi-chapter. It will probably take a while until I can post the next chapters, as they use to say creativity can't be rushed :)) But I will try to update it as soon as possible. I'm not sure how long this story will be, but I would say it will fall somewhere between 5 - 10 chapters. :)