A/N: This serves as both a prompt fill and a post-ep for 7x11. Rated M for a reason! Enjoy! :)

Disclaimer: I do not own Castle or the characters used in this story.

For Lou, who prompted me on twitter. I hope this is remotely close to what you wanted. Prompt will follow at the bottom of the page.

À Rire

à rire- (French) to laugh

The scent of sex drifts heavily through their bedroom, wrapping them both in a haze of passion that has only just begun. The satin sheets slide deliciously against her naked skin as she writhes beneath her lover's body.

She's been moaning incoherent thoughts ever since Castle slid down her body and pressed his talented mouth to the dripping, scorching heat of her center. The things that he does with his mouth should be illegal, but damn if he isn't fantastic at what he's doing.

She's skirting on the edges of yet another delicious orgasm, bracing herself for the earthquake of pleasure that Castle is expertly hurdling her towards, and she's so ready for it, so ready to come for him. But she wants to watch, wants to see the way he works his tongue in just the right rhythm against her swollen clit, while his fingers continuously slide against her G-spot.

Kate lifts her head from the pillow she's been thrashing against, forces her eyes to open and focus on the man between her legs and suddenly her orgasm seems miles away as she collapses against the mattress in a fit of laughter.

Thoroughly confused, Castle eases his fingers out of her and props himself up on his elbows so that he can get a clear view of his wife. Kate curls her legs towards her stomach as the laughter continues and although he has no idea what she's laughing at, Castle finds himself grinning at her like an idiot.

When she's calmed herself enough to look at him, she almost loses it again. Castle lays draped across the bottom of the bed, gloriously naked except for the hat she gave him earlier. It sits slightly crooked on his head now, and it's really a wonder that it's still on at all given their most recent activities.

But as funny as that is, it isn't just the hat that caused the laughter to bubble to the surface. It's the fact that in his left hand, Castle also holds the magnifying glass that she gave him earlier.

"Castle," she gasps out between laughs and the breath she's trying to heave into her lungs. "What the hell are you doing?"

"What do you mean?" he asks, casting her a sheepish look through the large magnifying glass.

"I know I asked you to leave the hat on, but why the hell do you have the magnifying glass too?"

He chuckles as he reaches for her legs, coaxing her to stretch them back out so that he's nestled between them again.

"Well Detective, given my recent career choice, I thought it would be best if I multi-tasked."

Another laugh bubbles out of her, more building in her chest and threatening to spill out, but she presses her hand to her mouth when he remains straight faced and serious.

"What exactly are you multi-tasking at?" she snickers.

"I'm closely investigating the female body's reaction while in the throes of passion, ya know, just in case I ever need to have knowledge of that."

She can't even stop it this time, the laughter spills out of her and only grows louder each time she chances a glance at him.

Castle manages to keep a straight face right up until Kate sits up and jerks the magnifying glass from his grasp.

But when she holds it close to her face and leans towards him, aiming it right in the center of his own legs, he can't hold the charade any longer and soon his billowing laughter fills the room.

"Kate-" he tries, but the seriousness of her face and the pose she's managed to hold on the bed disables him from continuing whatever he was about to say.

"Tell me, Castle, is this sexy?" She wraps her empty hand around his erection, giving him one firm stroke from base to tip and he groans as she continues. "Having a woman between your legs with a magnifying glass in one hand, while her other hand…"

He pounces on her then, using the weight of his body to knock her onto her back so that he can hover over her. In her moment of surprise she drops the magnifying glass and it tumbles off the bed and onto the floor.

"Oops, guess you won't be doing any more 'research' or 'investigating' right now," she whispers with a naughty smirk and before he can respond she wraps one leg around his hip and flips them over.

"It's my turn to do a little research of my own." She winks as she leans over him, letting the hard, pebbled peaks of her nipples brush against his bare chest.

"What research would that be?" he asks as his hands slide down her body to cup the twin mounds of her ass.

"I wanna see just how long you can keep that hat on."

He's still processing what she just said when she raises her hips and sinks down, taking him deep inside her body and immediately rocking against him. And just as quickly as the laughter began, it's replaced with gasps and moans.

She rides him hard, until her legs feel like jelly and she has to collapse against the broad expanse of his chest. The harsh sounds of their breathing fill the room for longer than normal and it could be due to the fact that she hasn't worked them both that hard in a while.

When she finally musters up enough energy to raise her head, she's shocked to find that somehow the hat still remains on his head.

Her chuckle vibrates through both of them and Castle's eye flutter open to focus on her.

"Managed to keep your hat on, that's pretty impressive, Castle."

He grins at her before leaning in to press a kiss to her lips that's entirely too suggestive after the round they just had. He slicks his tongue into her mouth just as she begins to pull away and he nips at her bottom lip in retaliation causing another giggle to slip from her mouth.

"Guess that means that I don't have to worry about losing my hat while I'm working, huh?"

She bites her lip as she looks at the hat then back at him.

"I'm never going to be able to look at you in this hat, or with that magnifying glass and keep a straight face. Maybe we better save the hat for the bedroom."

He kisses her again before pulling the hat off and tucking it into the bedside table drawer.

"What about the magnifying glass?" he asks.

"Oh, I think you'll find some other uses for it around here." Her wicked grin has him rolling her over and engaging in round three far sooner than either of them expected.

There are many things about him that Kate loves when it comes to sex. He's amazingly attentive, picking up on every little thing that brings her pleasure. He's open to new things and always up for an adventure. His sex drive could put teenagers to shame. But most of all, he makes her laugh, and if you aren't laughing during sex, then you're sleeping with the wrong person.

Prompt: "Castle making Beckett laugh during sex or vice versa. Fun, sexy times."

Would love to hear your thoughts! xo