A/N: This little extension was all but unplanned, and there is only one person who can get the blame for it. Krist0526, thank you for all the persuasive insistence. I really hope you enjoy this.

Disclaimer: All the characters belong to Andrew W. Marlowe, though they have found their own way into my heart.

It was well past midnight when Castle and Beckett got back home from The Hamptons Police party. They went straight upstairs, and while the writer continued down the hall to the master suite, the detective halted outside their son's bedroom. When she slowly pushed the door inwards, the hallway light spilled across the floor and crept onto Oliver's bed, revealing the sheets were empty. She immediately assumed he'd be sleeping with his baby sister. But when Kate checked the nursery, she found the crib was also empty. There was no one in Alexis' room, either.

Swiftly striding down the hall, she leaned around the master suite's door. There was one single lamp glowing near the fireplace, bathing the bedroom in a soft, pale light. Outlined in the halo of it was her husband's silhouette, standing next to the bed. "Castle, the kids are not in—"

He put a finger to his lips and beckoned her over to his side. When Beckett walked further into the room, the contour of several bulges stuck out above the wooden headboard. And then she saw them.

"Honey," Castle whispered to her, sliding an arm around her waist to pull her closer to him. "Look at our three children."

Kate couldn't help but smile at the endearing picture. Although, rather than three, there were eight occupants in the bed. Listing from right to left was Gigi, her doll in her arms, elephant Ellie and donkey Eeyore sitting on the top corner of her pillow, then Alexis, puppy Oscar, with his head resting on Oliver's knee, and last, Binky, his stuffed bunny.

"What do we do?" Beckett whispered, trying not to wake anyone. "Leave them here?"

"Sure, hon. It won't be for lack of beds in this house. We can sleep in another room."

"Perhaps we should take Romy with us." She reached out and tenderly stroked her daughter's curls. "She could fall off the bed."

Castle grabbed a couple of throw pillows from the nearest armchair and placed them along the toddler's sleeping form, thus preventing she could fall down if she were to roll to her right in her sleep. "There. All fixed."

"But she might wake up in the middle of the night, looking for us."

"Honey, Alexis is here with her. And what Gigi really wants is to sleep in our bed. And, oh look, she's already sleeping in our bed." Castle wound his arms around his wife and offered her a sly grin. "The good thing," he continued in a low and seductive voice, "is that, maybe, for this one night, we'll be able to enjoy some action without fear of being interrupted." Rick leaned in to kiss her but a voice stopped him. They both gazed down at the bed.

"I know I'm a grown up," Alexis mumbled, deliberately keeping her eyes closed. "And that, unfortunately, I'm traumatized for life. And I also know that, if it weren't for you two, this pair of perfect creatures wouldn't be sleeping next to me, but it is still repulsive to hear you talk about making love in front of me."

Kate felt herself blush slightly and she apologized in a low murmur. Castle's thoughts, on the other hand, took a different direction. "When did you get traumatized?" he inquired his daughter with interest.

"You really need to ask?" the redhead muttered, her eyes still closed. "Should I list it chronologically or by degree of trauma?"

Castle opened his mouth to retort but Beckett put a hand to his chest. "Don't listen to your father, sweetie," she whispered to Alexis, hitting her husband with a stern look. He seemed offended but said nothing else. "You want us to take Romy?"

"No, that's okay," answered Alexis.

"All right. Just bring her to us if she wakes up, okay?" The redhead nodded and nestled further into her pillow. "We'll be in the room at the end of the hall." Beckett grabbed Castle by the elbow and steered him toward the door. "Come on, Rick. It's late."

He immediately shook his arm out of her hand and stepped back to the bed's side. Exhaling a puff of air, Kate walked over to the dresser and opened a drawer. As she pulled out some fresh pajamas for them both and took her robe that was draped over a chair, she heard Castle whisper something to Alexis.

"If you want to spare these two creatures a trauma like yours, you'll keep them inside this bedroom so they won't be seeing anything they shouldn't."

As soon as Beckett heard him utter that improper comment, she returned to his side. "Castle, enough." She grasped his arm again and dragged him to the exit.

Out in the hallway, he started closing the double doors but then stuck his head back inside through the narrow opening. And again, Kate heard him whisper something. "Rick!" she growled halfway down the hall.

Castle quickly pulled the french doors shut and barely a second later something seemed to hit them at the other side. With a mischievous smile, he turned around and strolled over to where she was waiting. When he looked up at her face, he saw she was frowning, directing at him a disapproving glance through narrowed eyes, her arms folded across her chest, the pajamas squeezed between them and her breasts.

He stopped three feet from her. "What."

She snorted, spun around and continued her way down the hall.

"Come on, honey." He trotted behind her. "Alexis knows I'm only teasingly messing with her."

"Yeah, well. I really hope you stop being such a funny jackass when Oliver and Romy are older."

Flicking the lights on, Beckett walked into the guest bedroom, tossed her husband's PJ onto the bed and got into the bathroom, closing the door behind herself. A minute later, she opened again and came back out, already changed and wearing her robe.

"Rick, I forgot our toothbrushes. Could you go—?" she stopped talking when her gaze rose up.

Castle was on the bed, lying on his right side, his head resting in the palm of his hand. The clothes he'd worn to the party were scattered around the floor and his pajama was still at the bottom of the mattress.

"You hot?" she asked, arching an eyebrow.

"Oh, you have no idea."

"Well…" Her gaze meandered down his naked body, pausing briefly around his middle, and then went back up to his face. "Maybe you should open a window," she suggested casually.

"Maybe you should open your robe," he answered.

"Hmm… I don't see how that could help. It would rather make things worse, in my opinion."

Upon hearing that, Castle grew alert and propped himself up on one elbow. Kate started pulling at the belt very slowly. Barely blinking, his eyes fixed on her hands, staring intently at her fingers untying the knot. He expected to see her in her sexy sleeping shorts and a tank top, but when the front of the robe fell open, his jaw dropped and he stopped breathing. She smirked innerly at his reaction; it was exactly what she had wanted.

"You're wearing… lingerie," he choked out in a strangled, dry voice.

"I am."

Castle continued staring agape at her, with a dumbfounded expression on his face, as if he was suddenly unable to tear his eyes off her undergarment, completely enthralled by it. And how could he not be? The tiny —racy and mind-blowing— red lace set of sexy underwear left no room for the imagination. It pretty much looked like she wasn't wearing anything at all.

With the graceful moves of a cat, Kate walked up to the bed, climbed on it and crawled over to Castle, swinging a leg over him to sit astride his middle. Her hands pressed into the pillow at either side of his head and her hair cascaded down around them, the soft ends tickling his cheeks. Castle gulped and his gaze travelled south to her breasts. "You wore that all evening?" he asked in a raspy whisper. "Underneath your clothes?"

Beckett arched her back, pressing down to him. "I did," she purred into his ear, her voice low and silky. The nails of her right hand scraped across his pecs and she felt his stomach muscles twitch beneath her.

"God… Kate," he breathed out, his hands trailing up the sides of her waist, caressing her warm, soft bare skin. "Had I known, I would have dragged you to a dark corner and made you mine right there."

"Reeeally?"

Pushing herself backwards, she rubbed her butt against his growing hardness, teasing him. He drew in a sharp intake of breath, his eyelids slamming shut instantly and a low growl rumbling deep in his chest. Beckett grinned, pleased. She loved to drive him crazy, make his mind go all hazy and foggy with incoherent thoughts. But she also couldn't withstand that ironically sad, agonizing face of his for long, so she bent down to cover his mouth with hers but stopped two inches from his lips. "You locked the door?"

"Yes… No."

Letting out a huff, Kate pushed herself off Castle and crossed the bedroom in a sprint, bestowing him with a very nice view of her barely covered ass. Turning the lock, she spun around and leaned against the door, a sly smirk creeping onto her face. He grinned back, looking at her with a mixture of desire, challenge and anticipation. She held the tempting pose as long as she could, and then, in three quick strides, she rejoined Castle on the bed, jumping onto him when she reached the foot of it, making them bounce on the mattress, a laugh of delight leaving her throat. She straddled his waist again, knees pressed at either side of him, and sealed her lips eagerly with his. Castle's hands moved around her back and unclasped her bra, which was quickly shaken off and flung to the floor.

Just like a minute before, Kate moved a few inches up her husband's body and slid back down, bumping against his erection, stroking it with her butt cheeks. As she did, she started realizing just how turned on she actually was, just how needy she actually felt. Pressing her chest flush to Castle's, she tilted her rear slightly upwards and began moving faster back and forth, rubbing herself against him, taking great pleasure in the friction where she most needed it. His hands roamed her entire body, touching her everywhere, threading through her hair, cradling her neck, cupping her breasts, tracing the smoothness of her thighs, palming her butt cheeks —gripping, urging her on and on.

Their kisses became as urgent as their movements, tongues wrestling inside both their mouths. A frenzied sensation flooded Kate, hot and overwhelming, and she felt the pressure already building up, deep down in her underbelly. Just the simple act of rubbing together was doing it for her, making her blood boil in her veins, her heart thump hard and fast inside her chest. She knew Castle was victim of the same overpowering force. He nibbled and sucked on her lips with earnest passion, his hands stroked her body harder, and his pelvis kept twirling in small circles, bucking up into hers with every back-and-forth of her hips, increasing the surface of rubbing.

Dangerously close of losing all control, Beckett managed to slip a hand between their compressed bodies. The second her fingers grazed Castle's length, he twisted and flipped them over roughly, pinning her down to the mattress, leaving her breathless. He swooped down to steal a quick, erotic kiss from her lips, and then began assaulting the column of her neck. She tilted her head and sunk her teeth into his earlobe, sucking it into her mouth to run her tongue over the tortured, soft flesh. Sliding his right leg between hers, he applied pressure to her scorching center. Trapped beneath his broad frame, all she could do was moan loudly and push her hips down against his thigh, desperately seeking more friction.

To keep her from moving, Castle wrapped his hands around her wrists and started slithering down her body, drawing a straight line with his lips from her sternum to her navel, making only a small detour to circle her left breast, his mouth closing around her tight, swollen nipple. When his lips came upon the barrier of her panties, he continued his descent over them and placed a kiss right there, in the middle. It sent sparks shooting through her, igniting a current that electrified her, setting her nerve endings on fire. His breath was incredibly hot and tantalizing, blowing against her pulsating core through the lacy fabric. A wanton sound left her mouth, her eyes rolled to the back of her head, and her fingers —still prisoners under Castle's strong grip— fisted a handful of sheets, her knuckles turning white.

Two fingers slipped under the waistband of her panties. With her eyes tightly closed, she followed their path as Castle dragged them slowly down her legs, removing that last piece of clothing off her. When she was completely naked, he pressed his lips to her knee and then moved up, leaving a trail of tiny kisses along the inside of her thigh.

Kate felt her husband's blistering warm exhale half a second before his mouth was on her, unbelievably, unbearable, agonizingly, and sweetly torturous. Her entire body seized up. Her mouth opened into a soundless cry, her toes curled, and her knees tried to bend, but the weight of her husband's torso was resting on her legs, preventing her from moving them.

"Ca— Castle…" she breathed out with a choke, her heart hammering in her chest. "Castle… No…"

He didn't stop, either because he didn't hear her or because he didn't want to. His tongue flicked and her upper body jerked upwards, her spine bowing into a perfect arch. All of her muscles strained, fighting against the combusting fire starting to rush through her, because she was not ready to let go and surrender to blissful release yet.

It took everything that she had to reach down with a trembling hand and tug at Castle's hair, pulling him away from her. He rose up on his knees and met her hooded gaze.

"Just… give me… a second," she begged weakly, out of breath. "Please…"

He seemed reluctant but complied, giving her a short respite. Her head fell back onto the pillow and she closed her eyes, trying to slow down the erratic beating of her heart. Castle bent forward and pressed his moist lips to her feverish skin, softly kissing the valley of her hipbone. After pulling in a few more deep breaths, the blazing tightness simmered down a bit and she regained some control on her overstimulated body. Castle was distracted, dropping tiny kisses on her stomach, and so, she took the opportunity to tackle him on his back, taking him by surprise. In the same quick motion, she positioned herself above his pelvis and sunk down onto him in one smooth slide. They both moaned in unison, her inner muscles clenching around him. His lids closed over his eyes, and he placed his hands firmly on her hips, his thumbs dipping into the creases of her inner thighs. Kate bent her chest down onto Castle's and brushed her lips over his in a sloppy kiss. Dragging her hands along his forearms to grasp his wrists, she brought his arms up and placed them on the bed at either side of his head, weaving her fingers through his, holding on tightly to him.

And then she started moving slowly, rocking her hips against his at a delicious tempo. He began moving with her, the two of them completely synchronized, performing a dance of lovers that had been perfected through years of practice.

With her eyes screwed shut, Kate pressed her forehead to Castle's and increased the pace gradually, the tips of their noses touching, her fingers tightening around his. The gaspy breaths they shared between them very soon became a string of quick, shuddering pants, only interrupted by an occasional groan or whimper when they neared their climax.

Sooner than expected, her orgasm exploded within her and strong waves of pleasure washed over her. She slumped down, sinking into Castle's chest, panting heavily and completely spent. He immediately looped an arm around her back and flipped them over one last time, rolling on top of her. He rocked his pelvis into her twice more and found his own release. Sweaty and heaving, he fell face up next to her.

A full minute ticked by as they listened to the deep silence in the house and the distant murmur of the ocean, outside the windows. When his heart rate slowed down to an almost regular beating and his breathing allowed him to speak again, he said, "Three and a half weeks without sex is way too long."

Beckett smiled and rotated toward him, draping her leg loosely over his thigh. "Agreed." Castle slid his arm around her back and pulled her closer against his side. She traced the line of his jaw with her fingertips and looked up at him out of the corner of her eye. "Perhaps we could have Alexis babysit more often," she murmured, leaning on his shoulder and pressing her lips to the hollow at the base of his throat.

He looked down at her and grinned. "That can be arranged. Meanwhile…" With a wicked smile, he gently pushed her back flat to the surface of the bed. "We've got a few more hours left until morning and I intend on making every second count." And then he slid down the front of her body. This time she was going to let him please her as he liked. Relaxing down onto the mattress, she let her legs fall open and curled her fingers into the sheets again, bracing herself for an even more intense round two.

Thank you very much :)