At first it seemed like any other evening. Kate Beckett was lying on her bed, naked, with her fiancé's head between her legs.

Because they were at her apartment rather than his, she was loud tonight, not bothering to hold back her moans and cries of pleasure as she writhed under his ministrations, her fingers digging into his hair.

But then, abruptly, Castle lifted his face away from her and looked up into her flushed face. "Hey, Kate?"

She stared down at him, dazed and confused. "Uh?"

His fingers were still lightly stroking her, but her whole body was tingling, missing the firmer, hotter touch of his all-knowing tongue.

"How many mystery writers does it take to change a lightbulb?"

Beckett let her head flop back onto the pillow, exhaling loudly. "Castle, what the hell? I was so close."

He leaned in and gave her a long, slow lick, and then said, "Two. One to screw it in most of the way, and another to add a surprise twist at the end."

She groaned and closed her eyes. "That was terrible." Her eyes snapped open again an instant later when she felt his tongue on her again. "Ohh. Ohh, Castle, yes, right there."

He lifted off again. "Here's another one. What do you get when you cross a joke with a rhetorical question?"

"Oh my god. Why are you telling bad jokes now, of all times?" She pushed herself up onto her elbows. "Should I just get myself off?"

"Those jokes weren't that bad," he pouted. But he wrapped his strong hands around her hipbones and held her in place, bending his mouth to her for another long, dizzying moment before he once again stopped.

"I was just reading this article-"

"You have got to be kidding me!"

"-about a research study that found that women have better orgasms when their partners make them laugh."

She blinked up at the ceiling.

"Really?"

"Yep," he murmured against the tender skin of her inner thigh. He gave it a little nip and she gasped, twitching. "Let me know if that's working out for you," he added, and then he put his mouth back on her once again.

This time he didn't stop. He licked and sucked strongly, holding her down, until she burst apart in a beautiful rush, screaming his name as her vision went white.

As she slowly floated back to awareness, Beckett looked down again and saw Castle watching her, a small smile on his face. His fingers were still between her legs, moving gently against her.

"Research also indicates that almost seventy percent of heterosexual women sometimes fake their orgasms," he said, and smirked. "No offense, but I don't think you're that good an actress."

"I don't need to fake it," she panted, running her fingers affectionately through his hair. Her limbs felt blissfully limp. "Not with you."

Pleasure and pride glowed on his face as he lifted himself up the bed to kiss her. She tasted herself on his lips, and her breathing quickened again as his hand slid along her curves.

"So how did the laughing thing go? Because I have more jokes," he promised, waggling his eyebrows. She chuckled softly and shook her head, reaching up to capture his lips again for a quick kiss.

"You don't need the dumb jokes, babe. You make me laugh all the time just by being you." She paused. Maybe that hadn't come out quite right. "Anyway," she added hastily, "you also don't need tricks to make it better for me. You know that, right?"

"I just don't want it to get boring," he said, his tone serious, but she saw the twinkle in his eyes. "Just trying to keep things fresh."

"Well, you're certainly-" but she trailed off on a gasp as his wandering hand closed around one breast, squeezing firmly.

"Did you know that 29% of women can orgasm from nipple stimulation alone?" he rasped against her mouth, brushing his fingertips across the tip of her nipple. Her back arched and a soft moan caught in her throat.

"Oh god," she breathed, writhing on the mattress as he closed his fingers around the nipple and squeezed, hard, sending a delicious jolt straight through to her core. "You're not really going to-"

"Maybe some other time," he interjected, grinning a little. "Can you imagine these research studies, though? We should sign up for something like that sometime."

"I'm not having sex on a lab table with a bunch of scientists watching," she objected, arching into his hand. He pouted a little.

"It could be fun. And advance the cause of scientific understanding."

"No."

"Anyway," he went on, rising up on an elbow to loom over her, his erection nudging at her thigh, "they don't do it on lab tables. They do it in MRI machines."

"Oh, of course," she scoffed, rolling her eyes. "That's so much more romantic." She turned her head and found the soft underside of Castle's jaw with her lips, her teeth scraping lightly across his afternoon stubble. He hissed when she sucked at the vein in his neck, her hand gripping the meaty muscle of his shoulder.

"They put the woman in the MRI machine," he continued, his voice breathy with arousal, "with electrodes attached to her-"

"I don't want to know!"

"Head. Her head, Beckett, to measure brain waves."

"Oh." She chuckled sheepishly. "Yeah, that makes sense."

"Speaking of brain waves..." His hand trailed across her stomach and slipped between her thighs again. "One of those studies found that just thinking about being touched causes the same brain activity as actually being touched."

Kate quirked an eyebrow, meeting his gaze. "Really? That's ... actually kind of interesting."

"Yep." He nodded. "They put the woman in the MRI machine and tell her to imagine her lover touching her." His hand hovered just above the junction of her thighs, not touching her, but close enough that she could feel the heat of his fingers. She pushed her hips up off the bed, seeking, but his hand moved with her, refusing to touch.

"Castle," she moaned, her whole groin throbbing with anticipation.

"And when the woman is thinking about what that would feel like," he husked into her ear, "they observe the brain activity, and it's the same as when they tell her to touch herself."

In almost involuntary response, Beckett's hand came up off the bedspread, moving toward the aching need between her legs. But Castle batted her hand away.

"Uh-uh," he cautioned, smirking into her eyes. His hand was still just above her, tantalizing with its presence.

"Oh god," she whined. "Touch me, Castle."

"Are you imagining me touching you?" he whispered in her ear, and she shuddered strongly.

"Yes," she got out, "and if you don't do it soon I swear I'll-"

Her threat was cut off in a wordless cry as his fingers finally closed that tiny distance, landing unerringly in just the right spot. Her eyes fell shut as pleasure spread through her body, rippling out from the press of his fingers.

He leaned over her, his mouth still next to her ear as his body shifted above her, his fingers stroking her. "Now imagine me inside you," he urged silkily, making her moan again as his hot breath tickled her ear and his fingers teased.

"I'm done imagining," she panted, and reached down to wrap her fingers around him and pull him between her thighs.

He didn't resist, and from the groan that escaped his lips when he sank inside her, she knew that he had been teasing himself as much as her. She lifted her knees and spread her palms across his broad bare back, pressing him closer. Words were temporarily forgotten as they moved together with increasing urgency.

Afterward, they lay side by side, sweaty and breathless.

"So this is what you've been doing, late at night, when you claim to be writing?" Beckett needled, flopping her head to the side to look at her fiancé's profile. "Reading about sex research on the internet?"

He grinned, his cheeks turning slightly red. "Um. Well, you know how it is. You start off googling something perfectly innocent for book research, then you click a link that looks interesting, and next thing you know it's two a.m. and you just spent hours reading the latest discoveries in the scientific journals."

"So, not just downloading porn, then." She narrowed her eyes at him. He shook his head emphatically.

"I swear, Beckett. Peer-reviewed studies in scholarly journals about the physiology and psychology of the female orgasm. Like the one about humor and laughter. It's really fascinating."

"Uh-huh," she said skeptically. "Well, just in case, I think maybe I better check out your hard drive."

His eyes sparkled with merriment. "That's what she said," he exclaimed gleefully. And they both burst out laughing, reaching for each other.


Author's Note: This story illustrates the consequences of allowing an obsession with fictional characters to take over your brain, to the point that you can't even read an article about scientific research without immediately jumping to "what would Richard Castle think of this?" It's a sorry state of affairs, it really is.

All scientific facts and factoids contained in this story can be found on the internet, which of course does not necessarily mean that they're true.