A/N: Short little thing. Headcanon fic. Every Friday morning when they're not too busy, Beckett drags Castle down to the precinct early to spar with her in a couple rounds of kickboxing. Rated T? Sure.

"Those eyes may be closed, but don't think I don't know you're awake," Beckett said walking across the room. She had already slipped into a white tank and yoga capris, hair slicked back into a messy bun as she packed her toiletries and extra clothes for work. Castle lay flat on the bed, head burrowed into his pillow with his hands underneath, clinging for dear life not to be ripped out of his comfort just yet. "You haven't moved since I got up."

"What? Am I really that bad?" he asked lifting his head. Zipping her duffel bag she just smiled, eyeing him a bit before answering.

"I'm now convinced your constant movement, it's all your questions trying to wake you up."

After making a face, he planted it back down into the pillow, resisting her pull again. She walked over and sat on his side, rubbing her hands up and down his back before nestling her chin by his neck, whispers flowing out, seducing him to wake.

"Babe come on," she urged him. "This is the hardest part. We've done this a bunch. You know once we're goin' you'll be okay."

"Thuh shon izzn ewhen uhf yeh," he protested into the pillow.

"No, the sun isn't up yet, but I wanna get there early to reserve the mat just for us." He wiggled a bit, still refusing to make any movements that required leaving the sheets. "Unless…" She dragged out her words, knowing he'd surely shoot up and start moving. "…unless you want someone else to spot me, you know, being all heated and…wet."

He flipped onto his back, eyes widening to keep out all sleepiness, and set a hand atop her thigh. "No–right, I'm-I'm there, I got you babe." He blinked hard, twice for good measure, fighting the desire to even close them anymore. She touched a hand to his cheek as she smirked, then met his eyes, nodding to further encourage him to get up. Grinning bright at him, he managed one back the moment she flashed it into his eyes.

And it was that moment the morning's darkness washed away in her glow, warmth pouring over his body to remind him he didn't need the sun.

–

"Are those new?" Beckett suited up her hands over on the mat, watching Castle walk in with his dark gray beater and red shorts, shorts that draped quite perfectly over his…assets.

"I haven't had the chance to whip 'em out yet. It's been a while," he mused as he walked over to her. Grabbing for her hands, he went and wrapped them himself, careful and concentrated as he weaved the cloth between each finger.

"When was the last time?"

"For what," he said, securing the wraps on both hands. He watched her fingers flex a couple times before walking over to their duffel bag to grab his gloves.

"Oh you know, when I last kicked your ass," she called out. Slipping into his gear, he shot a glare, pursing his lips as he strode slowly back over.

"Such fighting words, Detective."

"Am I wrong," she teased, stepping up into him, just a few inches from his face. He didn't look so tired anymore.

"You–well, no," he said. Off her growing smile he continued. "But-but–that was another day. Today is today, not another. And today we will end this with me over you…or on top of you."

"Okay then Mr. Semantics," she said tapping her fists on his. "My husband might request you weigh easy on me, but don't think much on it. He forgets how rough I take it."

"We still talking about kickboxing?" he said as they backed away from each other. She bit back a smile as they assumed their stances, beginning to circle each other.

She threw the first hit that led to a successful series of hits, but he countered her surprisingly well on about fifty percent of them. She grinned at his blocks, and he smiled at all of her blows, wincing in pain, but still admiring her for every one. Each moved swift enough, fluid enough, and to the average eye, you'd see it, believing it to be just a decent fight.

However while first a battle of technique, it also possessed great energy and grace, like that of some dance. In each swipe, each hold, each toss or flip, their moves together flowed in a continuous burst of passion – one deep inhale and one longer exhale of breath, unbroken all throughout. The rhythm continued to surge through them as they executed their moves on each other, their groaning, heaving, and panting the soundtrack to their footing.

"Your stamina's improved," she managed in between blows. She dominated him for a bit, but he deflected her last few taps to muster up a reply.

"You can thank my wife for that," he breathed out.

An airy chuckle flew out her mouth as she maneuvered her way over him, nearly locking him into the intended angle to finally nail him, but with one brush of his fingers along God-knows-where, her torso stunned, immobilized for a few seconds before descending flat on her back. Mouth split open, she choked a little, but not out of as much pain as she expected. He dropped down, catching himself with his hands before crawling over her, pinning down her body with the full breadth of his, securing her there. Assessing his smug face, too sly and satisfied, she wagged her finger at him, his stunt echoing from a long night together just a couple weeks back.

"We said nothing about those moves," she said gathering her breath.

"Yeah, we established nothing. So since nothing was said, I thought any move was fair play."

"Well you're wrong," she insisted, suppressing a smile. "This is not our bedroom, Castle."

"True. Except it doesn't matter where we are, you realize I know your body much too well and I can't help that. It's like a reflex!" She shook her head in response while he wiped back her strands of hair, matted with sweat against her flushed skin. Despite both their wear, both fashioned pleased faces as they lay still on the mat.

"Round two?" she asked, tracing her thumb along his jaw.

"If you're looking for another beating, yeah," he said. Shaking her head again she scrunched her lips, letting her hand slide down his neck to hook the collar of his shirt.

"I was um–thinking more along the lines of the storage closet," she started. Her eyes flicked down towards where their bodies linked up, curve to curve, heat rising in between, before dragging those greens back up to meet his blues. "You know, so you can remind your wife just how well you know her body."

With wide eyes, he blinked hard, finding the strength not to prove it to her right then and there. Damn did he love her. "Oooh. I like that."

"Yeah? Me too," she said laughing, pulling him down for a kiss. They exchanged warmth for a moment, but after a second, she broke off, pressing his chest up. "Can we just–remember to check for each other's clothes this time?"

He lowered his head, eyes narrowed at her look toward him. "You're tellin' me? Seriously? Have we forgotten who left their bra to be confiscated and never seen again? And I liked that one, it was perfectly–"

"If I came forward it would've exposed both of us," she defended. He furrowed his brows, holding his firm gaze on her.

"Yeah and whose fault is that? Lost bra versus exposure. Neither would've been a problem if you'd just remembered–"

"Will you just shut up and let me kiss you," she said gripping his neck. Without another word he obliged, and dove for her face once again, doing the dance they did best together.

And it tasted like the sweetest love on a Friday morning.