A/N: This is my second contribution to the May 2018 Castle Pornado. This story takes place in the "Life of Sound" universe, but you can read it without having read the other stories in that series. All you need to know is that in this universe Castle is a Broadway musical composer and Beckett is a violinist/singer.

If you read "Reverberations," the third story in the series, you may recall that it makes reference to a sexual interlude in a dressing room during a show, which Beckett refuses to repeat despite much urging and many opportunities. This little PWP describes that encounter. It takes place in between "The Life Of Sound" and "Root Position."

I hope you enjoy it. Thanks for reading!

"Good first half, Mr. Castle," said the stage manager as Castle arrived backstage, flushed and cheerful, having exchanged high-fives and compliments with many of the cast members along the way.

"Thanks," he replied, directing his smile at her. "It's nice to be back."

"Do you need anything?" she asked, raising her voice to be heard over the sounds of many voices as the performers rushed to their places to rest up and prepare for the second act.

"Nope, I'm good," Castle called back. He moved toward his dressing room at the rear. "I'll just be in here if anyone needs me."

He let himself into the dressing room and immediately shrugged off his suit jacket, draping it carefully over a chair. He unbuttoned the top few buttons of his dress shirt too, needing to cool off a bit. Outside the theatre it was February and the wind was howling, the snow piled up on the sidewalks, but here inside, he was sweaty from exertion and the heat of the stage lights.

Most performances of Castle's rock musical Storm Surge were conducted by the show's regular conductor, but once in a while the producers asked Castle to make an appearance at the podium. Usually it coincided with some kind of special event or promotion; tonight it was a charity fundraiser for children's cancer research, and he had been only too glad to agree to lend his star power to the cause. His fans loved seeing him conduct.

On this particular occasion, there was only one fan on his mind: his new girlfriend, Kate Beckett. They had been together for about two months now, and although he knew Kate had seen Storm Surge before, this was the first time she was seeing him conduct it, and her first time seeing it since they started dating. He'd actually felt a bit of nerves at the beginning of the show when he first stepped up onto the podium, knowing that Kate was up there in his luxury box, watching him.

It wasn't that he feared making a fool of himself in front of Kate; he'd already done that plenty of times anyway. But he respected her opinion as a musician, and he knew that in her many years of sitting at the head of an orchestra she'd seen a lot of conductors, good and bad. He just wanted to be sure to make a good impression.

He crossed to the little sink in the dressing room and splashed some water on his face. As he was drying off with a paper towel, he heard a soft rap on the door.

"Coming," he called, and quickly moved to open the door. His eyes widened when he saw his girlfriend standing there.

"Kate?"

"Hey," she said breathlessly, stepping forward. "Can I come in?"

"Of course." He moved aside, closed the door behind her after she entered the room. "How did you talk them into letting you back here?"

"Didn't need to," she shrugged. "They recognized me."

"Ah, that makes sense." He supposed that it wasn't a surprise; the news of their relationship had spread like wildfire through the musical community.

"I guess so." Kate put her purse down on the counter and turned to face him, and he was surprised to see that her skin was tinged with pink, her breathing a little faster than normal, as if she had come rushing down here with some kind of urgency. Had the show been that bad?

"Is something wrong?" he asked with a frown. Kate reached past him to the door and twisted the lock.

"Yeah," she answered huskily, grabbing both of his hands with hers. "Your hands aren't on me. That's what's wrong."

She tugged his hands to her hips, and it finally clicked, Castle's mind belatedly shifting into gear. He'd been so worried that Kate would have something critical to say about the show... but that wasn't it at all. She wasn't upset; she was horny.

"So I take it you liked the first half?" he tried, using his grip on her hips to pull her closer until her breasts brushed his chest. The way her breath caught told him everything he needed to know. He bent his head to nip at her jaw and she whimpered softly, lifting one hand into his hair, gripping it tightly.

"I liked watching you," she gasped. Her other hand found the opening of his shirt, gaping where he had opened several buttons, and slid inside, her fingers cool on the bare skin of his chest. "I couldn't take my eyes off your hands."

She turned her head to kiss him, and he took the hint, getting his hands into motion while their tongues slid sweetly against each other. He let one hand go sliding up the length of her spine - feeling her shiver - and took a firm grip on the base of her skull to angle her for his kiss. The other hand wandered across her back and finally curved downward to cup her ass. When he gave it a squeeze, she moaned into his mouth.

"More," she demanded. "I need your hands. Touch me."

"Really?" Castle could hardly think through the raging tide of lust. Intermission dressing-room sex had always been a fantasy of his, but it didn't seem like Kate's style. Then again, it was hard to deny the way her body was undulating, her back arching to press her ass harder into his hand.

He took a chance on moving his hand farther down, finding the slit that ran up the side of her skirt. When his fingers dipped between the folds of fabric, an electric thrill ran through him.

"Holy shit, Kate," he groaned. "I know you had underwear on when we left the loft."

"Took it off in the luxury box," she said into his ear, followed by a hot lick of her tongue and a nip of her teeth on his earlobe that sent another shockwave of desire coursing through him.

"Oh my god." His breathing sped up as he let his fingers explore further, dipping between her thighs to find her already dripping wet and swollen with desire, practically throbbing under his touch.

"Touch me," she said again, her voice almost a whine as her hips tilted forward, seeking his hand. She was sucking at his chin, dotting hot wet open-mouthed kisses along his jaw, scraping her teeth over the slight stubble there. Both of her hands were under his shirt now, clutching at his shoulders. She let out another moan as he stroked the tender skin of her inner thigh, so close to the heat of her.

She stepped backward, her hands on his shoulders encouraging him to move with her. Her back hit the wall and she arched, pressing herself against his hand. The movement drew his eyes to the low-cut neckline of her dress, the tantalizing curves of cleavage.

Castle crowded in against her and claimed her mouth again, kissing her deeply, bringing his free hand up to dust over her collarbones, tracing the line of her cleavage, and then cupping her breast through the silky fabric of her dress. His other hand was still busy between her legs, stroking her lightly, teasing as she moved her feet farther apart, opening herself up to his touch. His pants grew even tighter as he savored the feeling of her body against his, her skin under his fingers, her tongue in his mouth.

They hadn't been together long, but the sex had been - still was - incredible. They couldn't get enough of each other, and if there was one thing Castle had learned about Kate Beckett, it was that she wasn't shy when it came to physical activities. She never hesitated to let him know exactly what she wanted - and he was always very happy to give it to her.

Now was no different. She lifted one leg around his waist - her skirt pooling appealingly at the crease of her thigh - and her fingers wrapped around his wrist, pressing his hand more firmly against her. "Stop teasing," she demanded. He huffed against her cheek, torn between amusement and amazement.

"So bossy," he observed, and without warning he thrust a finger inside her. She gasped, her body jolting against him. Grinning, he pulled back to look at her face. It was flushed, her eyes a little wild, and he could see, to his surprise, that she was already close to losing control.

"Castle," she moaned, circling her hips against his hand. "How much time do we have?"

"Um..." Distracted by the hot grip of her inner muscles on his finger, he struggled to focus his brain on the question. "Ten minutes, maybe fifteen."

"Mm." Kate lowered her foot back down to the floor and loosened one hand from inside his shirt, dropping it down to his pants, palming him briefly and then flicking open the button and zipper.

"Fuck," he swore. His finger had slipped out of her, but his hand was still between her legs, trapped between her damp thighs, and his other hand was still on her breast. He could feel the nipple straining into his palm through the fabric, and he shifted his hand so he could rub his thumb across that tight little bump, scratching it lightly with his thumbnail.

"I changed my mind," she panted. Her hand dove inside his pants and curled around him, making his hips jerk involuntarily. "I need more than your hands."

Castle sucked in a harsh breath, his skin tingling from head to toe with anticipation. "Are you sure?" he managed. "Kate - you have that rehearsal tomorrow-" Kate hadn't given up on playing the violin, but she had agreed to another singing gig with her usual orchestra, and he knew that she was a bit nervous about it. And as before, he assumed that she wouldn't want to do anything that would risk affecting her voice.

But the way she was moving against him made it pretty clear that she wasn't going to let that stop her this time. "What are you saying, Castle?" she asked breathlessly, quirking an eyebrow with a wicked twinkle in her eye. "You don't want to fuck me right here in this dressing room, up against this wall, in the middle of your show?"

"I - ah, shit," he cursed as her hand made a slow stroke up and then back down the length of his shaft. "You know damn well I do, fuck."

She released him and reached over to her purse, producing a condom. Castle watched in a daze as she unwrapped it and then took him in hand again, rolling the latex down his shaft with quick, efficient movements. He had to clench his teeth together to keep from thrusting into her hands.

Then she lifted her leg around his waist again and used it to pull him closer against her. His erection slid through her wetness, making them both groan. His hand, still wet with her arousal, curled around the back of her thigh. He tugged her leg higher around him and thrust his hips shallowly, sliding his shaft across her clit, making her gasp again.

"Now, Rick," she said, more a plea than a command. Her teeth were digging into her lower lip, her chest heaving with urgent breaths.

Castle reached down and nudged himself into position. Just as his tip was pressing inside her, a sharp knock sounded on the door. They both froze, staring at each other, wide-eyed.

"Ten minutes, Mr. Castle," called the stage manager's voice. "Everything okay?"

He cleared his throat, took a good full breath from the diaphragm, and kept his voice calm and clear as he called back, "Yes, I'm fine. Ten minutes, got it."

"Great," the voice said, and quiet descended again.

"Good breath control," Kate murmured, a small smirk lighting her face, though he could still see the lust lurking in her eyes. He mirrored her expression, smirking right back at her.

"Thanks," he husked. And with a snap of his hips, he drove himself into her.

Kate cried out, her hands coming up to his shoulders, fingers digging in hard to steady herself. "Oh god," she moaned. "Oh yes. Just like that."

He released her breast and braced his forearm on the wall beside her head, his other hand still holding her leg up, holding her open for him. He pulled almost all the way out, slowly, teasing, and then slammed in again.

"God, Castle, yes." Kate's arms tightened around his shoulders, her hips rocking into his rhythm. "More. Don't stop."

"You're incredible," he panted as he began pumping steadily, fast hard strokes that had her mewling and writhing between his body and the wall. "You're amazing, Kate, fuck." He turned his head, seeking her lips, and they kissed, sloppy and breathless, little more than a wet messy slide of mouths as their bodies moved in perfect synchronization.

"You - I'm - " But whatever Kate was trying to say, she couldn't get the words out, her eyes drifting shut as the pleasure overtook her.

Castle lowered his head to her neck, finding that spot just beneath her jawline and fastening his mouth to it, sucking hard, and that extra bit of stimulation was all it took to send her flying. She didn't make a sound as she came, and some small part of his brain was impressed by the control she managed to hold on her voice while her body was shuddering fiercely against his.

But most of his brain was focused purely on the exquisite sensation of her inner muscles contracting around his length, and on how gorgeous her face looked as she gave herself over to her climax. It was all he could do to keep himself moving, to hold back his own orgasm and maintain the rhythm of his thrusts while she was coming.

As her trembling slowed, her eyes opened and found him watching her. "Oh," she breathed, her body twitching in surprise as she realized that he was still there, still driving into her, slower now. "You didn't-"

He grinned softly and brushed his lips across hers again. "Not yet. You first."

"Oh god." She clutched at his shoulders, gasping for breath. "Again? I - I can't-"

"Yes you can, Kate." He settled her leg around his waist and released it to slide his hand between their bodies, finding the place where they were joined, touching her with renewed confidence. "Come on, you wanted my hands on you, right?"

"Fuck," she swore, her teeth clamping down hard on her lower lip. "Oh. Oh god, Castle."

"Come for me again," he murmured, gritting his teeth as he thrust into her again. The pressure in his balls was building, almost unbearable. Kate felt so good around him and he knew he wasn't going to last much longer. He spread his palm wide along her lower belly, so that his thumb was positioned just right to hit her clit with each thrust of his hips. "Come on, Kate. Feel my hand on you? Come for me now."

"Castle!" she cried, and she was coming again, and he finally let go too, burying his face in her hair as he groaned out his release.

They stayed motionless like that for a long moment, their bodies entwined, hands gripping each other for support, both panting and gasping as they came down from the high. At last he pulled back, slipping out of her with a sigh. He put his hand on her leg again and lowered it gently to the floor for her.

Kate stood leaning against the wall, watching him as he threw away the condom and zipped up his pants. His knees felt wobbly, and he glanced over at her with a rueful grin.

"Not sure how I'm going to stand up at the podium for another hour," he commented. She chuckled softly, pushing away from the wall. Her skirt fell neatly back into place around her legs, and he marveled at how composed she looked, how elegant and poised. Her hair was barely even mussed, her makeup intact; she didn't look at all like a woman who had just gotten fucked against a wall during the intermission of a Broadway show.

"Sorry," she husked in a not-at-all-sorry tone of voice. She stepped forward and reached up with both hands to fix his hair, combing her fingers through it and smoothing it down. "I better get back up to the box. Break a leg in the second half, babe."

"Thanks," he said, still more than a little dazed by her. She smiled, patted his cheek, and slipped out.

Alone, he washed his hands in the sink and pulled his suit jacket back on, checking himself in the mirror. His face was a little flushed, his eyes a little glassy, but he looked okay. He looked a lot more suave and collected than he felt, that was for sure.

He sank into his chair and closed his eyes, taking just a moment to rest his legs and savor the phantom sensation of Kate's body against his, the slight hint of her scent that lingered in the air.

Then there was another knock on the door, and it was time to go back to work.

Hours later, lying in his king-size bed with Kate, both of them pleasantly sweaty and breathless, he turned to her with raised eyebrows.

"Soooo..." he said, grinning a little, "I wouldn't have figured you for the dressing-room-sex type."

She blushed hotly, squirming. "I'm not," she insisted. "It won't happen again."

"Oh come on, let's not be hasty," Castle said, rolling onto his side, caressing her hip lightly. "I know you liked it."

Kate narrowed her eyes at him. "That's not the point. It's not my style," she said firmly. "I just..." She gestured vaguely. "When I was watching you conduct..."

"You got turned on by watching my hands," he finished for her. "That's what you said."

She nodded, clearly still embarrassed. "Yeah..."

"But here's what I don't get," he went on. "Why now? You've seen me conduct before and it didn't get you that worked up."

She averted her eyes, her blush deepening even further as she pulled her lower lip between her teeth. Castle's eyebrows shot up again.

"It did? Really?" he asked, delight infusing his tone. "Even when we were on stage together, doing Messiah?"

"I hated you back then," she reminded him, grumbling, but the twist of her lips told a different story.

"You hated me and wanted me," he teased. His hand went wandering across her body, brushing over her breasts, down her stomach, across the tops of her thighs, back up over her hip again. "Did you watch these hands and imagine this, every time? All three Messiah performances? All those rehearsals?"

"Don't be smug," Kate chided, but the flush was spreading across her chest, and her eyes were dilating. Castle chuckled softly and bent his head to kiss her.

"Maybe I should conduct Storm Surge more often," he mused, his lips curving upward. Kate rolled her eyes.

"Maybe you should shut up, put those hands and that mouth to better use," she replied. She put both hands on his shoulders and pushed him downward, making her meaning very clear. Castle's grin only widened as he complied, sliding down the bed and settling himself between her thighs.

"Okay," he said, "and then I'll show you what else I can do with my baton."

The way her startled laughter turned to a long moan when he put his mouth on her was music to his ears.