Sounds

A/N: Takes place after 7x19, which I watched recently for the first time and absolutely LOVED! This is a little mature, but not too much. Hope you enjoy!

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Surprisingly, it hadn't taken much to convince Beckett to not let their fervent practicing of their shower routine go to waste. The loft was quiet, unoccupied, and he'd slipped one article of clothing at a time off her slender body, murmuring how much he longed to feel the triumph of winning.

"But we're not competing," she'd whispered, her smile evident in her voice as he kissed her now bare shoulder.

Castle had grinned against her clavicle as she slipped his button-up shirt down his back. "Oh, but we are. And I have a feeling we're going to win."

She'd giggled to herself as she ducked into the hot shower, dragging him in behind her. "I love that sound," he murmured, and lightly pinched her sides until she let out a less-controlled laugh, like champagne bubbles spilling over the rim of a crystal glass. She gasped, trying to tamp down on the laughing fit, before Castle pressed his lips to hers. They were wet and warm, and it took everything in him to pull back to smile down at her.

After a few more breathless kisses, he asked, "Are you ready?"

She pretended to look around, ensuring they had no audience. "Ready." She stuck her tongue between her teeth, grinning excitedly.

And they began their routine. Castle started, his deep voice echoing in the small bathroom. Then Kate joined in, her sultry, warm honey voice soothing over the ridges of his own. They sounded great together, both when singing alone, and harmonizing. Their movements were relaxed, fluid, and they even threw in the added dip they'd practiced in the living room, though more slowly, careful not to slip on the tiled floor.

When they were done, both grinning so hard their faces ached, Kate wrapped her arms around Castle's neck and brought his mouth to hers with one hand on the back of his head. "Thank you," she whispered, and despite the heat of the shower, he felt goosebumps on his lower back. "For not making me do that in front of all those people."

"You're welcome," he answered, and after a moment added, "You know, I figured…" He pressed another slick kiss to her lips. "All the better for me to enjoy." Then another kiss. "Maybe I decided I didn't wanna share."

She laughed again, nodding agreeably. "I'm all yours, Castle."

Castle pulled back, looking into her amber eyes, sparkling with delight. "It's not just your laugh, you know. I love the sound of your singing voice, too."

Kate blushed. "I do okay, I guess."

Castle shook his head, tightening his hold around her lower back. Their bodies were warm under the spray of the showerhead. He could feel her heart beating against his own chest, and her tanned skin was delicate and smooth under his hands. This might just be his favorite place to be with her. With or without the routine.

"You do more than okay. You're pretty good."

"Mmm," she sighed back, closing her eyes and pressing her forehead to his chin.

Gently, he maneuvered her out of the spray of water, inching her toward the wall of the shower. "You know what other sounds I love?"

"Hmm?" she asked, eyes flicking back up to meet his. They were heavy and relaxed, water droplets hanging from her eyelashes.

"How you get louder, more convicted, when we theorize."

"Louder?" she asked, one eyebrow inching upwards.

"Not in a bad way. You just get more… animated. Your whole body swells up with the excitement of figuring it out. With every piece we put together, confidence leaks into your voice, making you so…" He kissed her forehead lovingly. "Adorable. Pleased."

She grinned, and moved her hands from around his neck to rub down his back in slow, steady strokes. "I see…"

"Mmm-hmm. But you know what my favorite sound of all is?" He lowered his voice, taking one last step before her back touched the tiled wall. Her eyes lit up, realization dawning on her. Her face split into an excited, playful smile.

"What's that?" she breathed, hands resting just centimeters from his ass.

Never breaking eye contact, Castle slowly slipped a finger inside her, curling it until it hit just the right spot. Kate's eyes slipped shut and a ragged breath caught between her teeth. He angled his palm until it was flush against her, then dragged his finger back out, and in again.

She moaned. "Oh, Rick…" Just like he knew she would. God he loved hearing her say his name.

"That one," he said, and nipped at the side of her neck, sucking off the droplets gathered there. "I wanna hear it again."