Prompt: Double penetration, toy in the front and Castle in the back (or the reverse)

A/N: I chose the reverse giving me the potential for a sequel. Also, this is very explicit and detailed so if this is not your fort, please skip reading. If you do end up reading it, enjoy and do not forget to review.

xxxx

Castle chewed his lower lip as he sat on their bed, fumbling with a slim, black box in his hands. He flipped it up in the air and caught it again, turning his wrist to look at the time. He was waiting for his fiancée to come home. He felt a little guilt for last week when Kate opened up about one of her fantasies. While they usually put in their best afford to fulfill each others requests, Castle couldn't stand the last one she had. She wanted to have a threesome. He had flinched at first at her words and stared at her for the longest time, Kate's eyes faltering as she realized he was not okay with it. He would never be. He remembered how she flinched away when he tried to touch her telling her he was sorry, but he honestly couldn't bear the thought of someone else seeing her naked, let alone touch.

After a long moment of silence Castle finally explained that he had waited for Kate for four long years, watching her with a few other man. He remembered how he was jealous, but equally hurt over those men, because they were allowed to do what he wasn't. He had been in love with her for forever, he couldn't even remember the moment he fell for her, but he had to watch her with others and it nearly made him quit and give up on her. It was then Kate finally understood what he meant, rolling on top of him to press her mouth to his in a searing kiss. It was the last time they mentioned it, until the day prior to day when Castle just had to ask why she wanted another man join in their activities. His pride was hurt, thinking she wasn't satisfied with him. Kate made sure he would understand she was plenty satisfied with him, jumping his bones right in kitchen, taking him against the counter. It didn't last long until her teeth tugged his earlobe, a second round initiated where he took her from behind, her ass repeatedly engulfing his cock while three of his fingers found their way into her soaked pussy.

She liked to be filled. He got it right than and there. While he fucked her mercilessly, made her cum twice before he had let himself go, he was set on fulfilling at least the reason of her threesome idea. The next morning he told her she should head to the precinct, while he caught up with his writing. Instead of sitting in his office writing, Castle had put on a cap and sunglasses, making his way to a novelty shop on 7th Ave. to buy a little helper. All day his pants had felt a tad bit tighter and he was seriously considering to just jack off in the shower. He held off, the excitement over the prospect of fulfilling her fantasy winning over him. That is how he ended up sitting in boxers and a white button down on his bed, his back leaning against the headboard while a whole sea of flickering candles surrounded him. The box dropped on the bed as he heard the keys turning in the lock and he smirked when the door opened and closed, the familiar 'thump' of her boots being kicked off following.

"Castle?" Kate asked as she made her way to his office, noticing it was dark, the only light stream in the whole loft coming from their bedroom. She smiled and walked towards it, pushing the door open, gasping at the sight.

"Hello gorgeous," he smiled as he got off the bed, making his way to her to press his lips to hers in a soft kiss.

"What is this all about?" She asked curiously and shrugged off her jacket, taking in the sight of the room. A wave of anticipation rolled through her body, arousal already pooling at the lower portion of her abdomen.

"I have been doing a little thinking and I came to the conclusion I needed to buy you a gift," he said as he tugged at her hand and led her towards the bed, navigating her to sit down. He grabbed the box and handed it to her. Beckett eyed it with careful eyes, ripping it open immediately.

"Rick...," she rasped out with a mix of surprise and excitement, tearing the rest of the box away to reveal a purple vibrator. She carefully opened the plastic container it was in, taking it in her hand.

"Since I am not too keen on having someone join us, I do like the idea of filling you up. I figured this is an acceptable compromise," he grinned cheekily and Kate nodded, pulling at his shirt to crash her mouth into his. He stumbled at the impact, falling flat on top of her on the bed, his mouth fusing together with hers in a passionate kiss.

"You're perfect, you know that?" Kate mumbled against his lips, her hands making their way under the shirt to gently scratch her nails along his spine, causing Rick to shudder in her arms.

"Oh, so I have heard," he winked and smirked, nipping at her lower lip as he pushed himself up enough to untuck her blouse from her pants, quickly fumbling the buttons open to reveal the lavender satin bra she was wearing. He licked his lips and leaned down to kiss her breasts, his hands roaming her abdomen. She moaned at his ministrations, her back arching to press him closer to herself.

In a matter of moments they both shrugged off the rest of her clothing, leaving her in only her panties and Rick in his boxers. He helped her slide up the bed a little, his mouth firmly attached to her neck, sucking and nibbling at her skin, his hands cupping her breasts to knead them, tugging her nipples with his fingers. Kate's level of arousal climbed steadily higher with every touch of his skin against hers, the anticipation of what was to come making her squirm and impatient. She needed him, needed him to bury himself in her body as deep as he could.

Her arm slid up to his shoulder, trying to push Rick on his back, but he wasn't having it, pressing her down once more and rolling on top of her. He smirked at the frustration showing in her face, his lips pressing against hers to kiss the pout away. She responded almost instantly her mouth opening to let her tongue brush against his, moaning as her legs came up to trap him between them, pressing his boxer clad erection against her lower body. His bucked his hips, teasing her, causing Kate to gulp and pull away a little to gasp for air. He smiled at her and slowly slid down her body pressing his lips to her skin, nipping and sucking his way down to her navel. He flicked his tongue out dipping it into it, swirling around to tease her.

Kate's hips buck, the scent of her arousal filling Rick's nostrils. The need to taste her takes over him and he gently bit her hip, his hands tugging on her panties to pull them off her body. A moan escaped him as he slid his tongue over her inner thigh repeating the motion on her other as well. Soon his nose bumped into her the space between thigh and crotch, taking a deep breath to take in her scent one more. He felt lightheaded as he dipped closer and flicked his tongue over the engorged clit peeking out, swollen and red. She was really enjoying this.

"Someone is excited," he mumbled against her and opened his mouth, his tongue making a long lick from her opening to her clit, his lips swirling around the little nub before sucking it into his mouth. Kate groaned and grabbed his hair with her hand, pressing him harder against her lower body. Her muscles already twitching, Rick knew she needed more. He pulled away for a second blowing hot air on her sensitive core, his hand extending to grab the recently purchased toy. He looked up at Kate, whose eyes were black with arousal and want, her lower lip red and raw from sinking her teeth into it.

"Suck it," he rasped out as two of his fingers joined his mouth, smearing her arousal all over her. Kate moaned and nodded, leaning closer to close her lips around the toy. She scrunched her face a little at the taste and smell, but eagerly sucking it into her mouth, swirling her tongue over it. Rick groaned against her, rewarding her actions with two of her fingers sliding into her body. She clenched hard and moaned, her juices coating his fingers fast. He smiled and slowly eased them back out. Soon his middle finger pressed against her puckered hole, sliding the tip in as his mouth covered her clit once more. Kate released the toy in her mouth with a pop as she moaned loudly, relaxing at his touch, spreading her legs wider as he added a second finger to her ass, his tongue slipping into her pussy, his nose nudging her clit.

"Fuck it, Rick, please don't tease me," Kate groaned as he fucked her ass, his lips now sucking at her clit, his tongue flicking over the tip, making her squirm under his ministrations. He smirked at her and gently removed his fingers. He finally moved the toy in his hand to her opening, thrusting it inside with one smooth thrust, burying it deep as he set in on the highest setting. Kate slumped back against he pillow, screaming as his lips nibbled and sucked at her clit, her entire body bowing as she came. A string of curse words escaped her as he removed the vibrator way too quickly, stopping his actions altogether as he knelt up and leaned over to reach into the bedside table. He quickly found the remaining items he needed: a condom and a bottle of lube. Kate watched him through hooded eyes as he ripped open the foil package and grabbed the latex, easing it with one skilled move over the vibrator. He grinned as he noticed Kate still laying there, trying to catch her breath. He leaned over her to kiss her lips softly.

"Ready?" He asked as his tongue teased her lips. She nodded her head and wrapped her arms around him, kissing him once more while pushing him on his back. She was now the one hovering above him, her hands impatiently pushing his boxers down his legs. She licked her lips as she noticed his fully erect cock, the tip glistening with moisture.

"I see I am not the only one excited," she rasped out and leaned over to wrap her lips around him, sucking a little and brushing her tongue over his tip.

"I have been waiting for this all day," he moaned and grabbed her hair to pull her up. Kate swung her legs over his body, seating herself on his lower body, his cock trapped between the cheeks of her ass.

"Hmm, I honestly cannot wait," she purred and leaned down, pressing her mouth to his. Rick smiled and grabbed the toy once more, while Kate sat up and took the bottle of lube to uncap it. She poured a good amount of the clear substance on the condom clad toy and used one hand to smear it all over it. She wiggled her hips and smiled as Rick leaned back against the pillows, pulling her upper body down to press his lips to hers. She put her hands on the bed to steady herself, her hips raising enough to expose her ass. He pulled away enough to watch her as he moved the toy between her cheeks, rubbing it up and down, smiling as she bit her lower lip in ecstasy.

Very carefully he slid the tip of the toy into her body, twisting it from left to right. Kate moaned at the intrusion, one of her hands slipping between them to rub her clit lazily. She relaxed immediately and nodded her head silently as Rick pushed the toy in deep until it was all the way buried in her ass. Kate hissed and groaned at the sensation, moaning as his free hand joined hers, rubbing her clit while kissing her lips. She took a deep breath and wiggled her hips, signalizing Rick to start moving. He grinned and twisted his wrist the, moving the toy slowly halfway out and back in. She groaned loudly as she moved herself up enough to grasp his cock, lifting herself up to place him at her entrance. With one smooth thrust she fully sheathed him in her body, letting out a loud moan as he pushed the toy in all the way as well, filling her holes up to the max.

"Oh my God, Rick," she moaned as she started to move on him. He held the toy steady twisting the bottom of it to turn it on. The sensation of the vibrating toy in her ass as well as Rick in her pussy did it for Kate. Her thrusts grew sloppier and faster, her muscles quivering in her arms from the afford of holding her body up. To make things harder for her, Rick latched on to her breast, sucking and biting her nipple. Another scream filled the room and he groaned as well, his hand now thrusting every time she pulled back from him.

"Harder, faster, fuck...please," she rasped out and he bit her nipple, his hand speeding up the toy as she slammed herself down on him faster and harder. With one last tug at her nipple she let go, her entire body quivering and clenching around him. That was all it took for Rick, watching her come he let go as well, strings off cum filling her body as she clenched hard around him. She slumped down on him, her chest heaving and her breath coming out in loud puffs, her lungs desperately trying to refill themselves with oxygen. Carefully he eased the toy out of her body, turning it off while he threw it off the bed, his arms wrapping around her as he rolled them to the side. He slipped out of her and she squirmed at the loss, her eyes closed and her hair sticking to her sweaty face.

"Can we please do this again?" She panted as he cupped her face and nudged her nose with his, pressing his mouth to hers.

"Only if I get to be in your ass," he chuckled and kissed her once more, hugging her body to his, listening to her breathing even out as her lids closed.

THE END