"I don't steal things that belong to someone else." – Serena Kaye (4x05)

She moaned loudly in pleasure as he finally sinks down into her, spreading her wide and filling her like no one had before. Granted, it had been a long time, but there was more to it than just that. And she knew that. She acknowledged that. Maybe Kate should thank Serena Kaye. The woman's appearance had kicked her into gear, realizing that she couldn't just sit around and wait, but had to act, had to finally claim that which belonged to her. Yeah. She'd have to thank her. But later.

Castle let out a grunt above her, and she stared up into his face, mesmerizing the amazed and awed expression he wore, as if this was a dream come true. His eyelids closed as he groaned in pleasure as he nudged his hips just a few more inches forward. Her walls trembled and clenched around the intrusion, and she mirrored his groan, arching up into him, clawing at his shoulders, pleading with him to fill her completely. And he did.

He stilled then, buried deep inside her, allowing her to adjust to the invasion of her soaked heat. His large hand sprawled out over her heaving chest, resting over her heart, over the ugly scar that marred the skin between her breasts. Her eyelids fluttered as she glanced up at him, breath catching in her throat as he dipped his head down, replacing his tender touch with a gentle press of his lips, grateful and reverent. Her heart stuttered over the display of adoring affection, the look of awed love in his eyes.

"You're beautiful, Kate," Castle murmured against her chest, his hot breath caressing her sensitive flesh as he spoke. "So beautiful." He shifted up, claiming her mouth in a soaring kiss.

She closed her eyes and hummed into his mouth, overwhelmed with all the sensations her body was feeling. It just didn't seem possible that she could feel this way, but she did. It caught her off guard, but she decided to embrace it, and accept it. This was right. This was how it should be. Especially with him. His hand moved to palm her breast as he rocked his hips against hers, finally moving, finally giving her that delicious friction she so desired. Kate groaned and threw her head back, crying out in ecstasy as he hit that one spot inside her that rarely any man had ever touched.

Part of her was surprised he'd found it so quickly. But really, this was him, this was her Castle—her annoying tagalong who had spent so long observing her every move. So, it really shouldn't surprise her.

But it did.

Gripping his shoulders, Kate urged him on, whimpering and moaning as he thrust his hips back and forth in a steady and commanding motion. It felt so good. So very, very good. She had never been brought so close so fast before. This man was truly talented beyond her knowledge, and part of her was so thankful for that. Though, it had been a long time for her, so she shouldn't be surprised that she was already approaching the threshold so quickly. But still, even with that, this was rapidly turning into the best sex of her entire life.

She imagined, however, that a large portion of that had something to do with the fact that this man—this glorious man—had stood by her side through thick or thin, when others would have fled, he had stayed. Through it all, he had loved her in spite of all the times she had pushed him away, denied him that which they both craved. He loved her. And she loved him back. She really did, with all of her heart. Freely admitting to herself just how jealous she was of the allure that Serena Kaye represented, and what those feelings truly meant, had given her the courage to finally show Castle just how much she really did need him… want him, just him, as he was. That was what she wanted. To love him. And to have him love her.

And now they were in her bed, on the verge of making love for the first time.

It had happened so fast. One moment she was offering to buy him a burger to soothe his bruised ego over having to pay a rather exorbitant amount of money for the damage done to some modern art piece—even though in doing so he had unmasked a killer—the next they were tumbling into her apartment, ripping each others clothes off.

She closed her eyes and arched up into him as he dipped his head down to nibble at her neck, tickling her. Kate danced her hands down his bare back and grabbed his ass with one hand, digging her fingers into the plump flesh, encouraging him to go harder and deeper. He obeyed, pounding into her, rocking the bed with each downward stroke. Kate shoved her head back into her pillow, surrendering to the euphonic pleasure of finally having this, having Castle making love to her. It was everything she'd ever hoped for, and more. So much more.

"God, Kate… you're amazing," Castle grunted, ramming harder into her, sending sparks of pleasure bursting through her quivering body. He found her lips again, smearing a kiss against her open mouth, delving in a exploring with a hot and talented tongue.

She could feel his hips jerk, shuddering. She knew that meant he was close, just like she was. She squeezed her fingers harder into the plump flesh of his delicious backside, and he groaned, smirking down at her as he thrust one last time before he tensed and she felt him reach release, spilling inside her. And that did it. That was enough. That was all she needed to follow him. Clenching around him, Kate collapsed over the edge, screaming in undeniable pleasure as her orgasm cascaded throughout her entire body. Her mouth dropped and she cried out his name in euphoric bliss. It was the only name she ever wanted to cry out in ecstasy ever again.

Castle slanted his mouth over hers, silencing her cries of pleasure, continuing to thrust his hips with slow and steady strokes, prolonging her release. His solid weight hovering above her was like a warm blanket, and she basked in its embrace. She reciprocated his kiss, wrapping her arms around his torso, keeping him above her, skin to skin.

Kate nuzzled her nose against his, and pressed a light kiss to his lips, smiling up at him as he panted heavily, regaining his breath. She swallowed heavily a she thought of his declaration of love and her guilt over denying him an answer. But now, after what they'd just done, and feeling the comforting and reassuring presence of his body over hers, she no longer felt afraid to give voice to her feelings.

"Castle?" she breathed out into the soft silence of her bedroom.

"Yes, Kate?" he asked, shifting his weight above her, one hand wandered down her side, lingering along the surgical scar, the touch of his fingertips tender and loving.

She averted her eyes and licked her lips nervously, wiggling uncertainly underneath him as she sought out as much courage as she could. Flicking her eyes back up to his, hopeful and bright. She smiled, breathing in deeply, and finding the strength from the welcoming closeness of his body.

"Kate?" Castle prompted, caressing her side encouragingly, his thumb teasing the underside of her breast.

She bit her lower lip and smiled affectionately up at him, already knowing he was hoping for a second round. She was too—many more rounds, everyday, every night, hopefully for the rest of her natural life. But first, she had to set the record straight, had to fix her past mistakes and let him know the truth. She gently nudged him back until they could look each other properly in the eyes. Kate gazed up at him, letting her eyes reflect all that she had left unsaid for so long. And then she finally voiced it, with all the emotion and gratitude she felt, emboldened by not just their recent activities, but also by the tender, hopeful look in his eyes.

"I love you, too."

prompt from anon found on the casteficpromoter blog: Eye of the Beholder AU: Beckett's offer to take Castle out for burgers escalates into some hot sex back at her place.