co-authored with airbefore

His hand is warm on her thigh, slipping up under the hem of her dress, caressing her skin with feather light touches. Kate smiles at the woman sitting across from them and squeezes her thighs together, tries to still his questing fingers. She can see him grinning in her peripheral vision, a smug light dancing in his eyes.

"So, Rick, how's the new Nikki Heat coming?"

The tips of his fingers brush over her and she feels him go still, his arm vibrating with tension where it's pressed up against her stomach. She's not wearing underwear, impossible with this dress, and can tell from the way his throat is convulsing that it was the last thing he had expected when he started this little game.

"It's good for the most part. Still trying to work through the case though."

He drags a finger through her arousal and she has to bite back a moan when he slips inside her, his palm pressing hotly into her inner thigh. He pushes his finger deeper, curling at the first knuckle in the way he knows drives her insane, and she grips the wooden seat in an effort to stop her hips from bucking up against him. He's smiling, engaged in a goddamn conversation like the pad of his thumb isn't this close to brushing across her clit, like he's not about to make her moan his name at a table with another best selling author.

He takes a sip of his scotch with his free hand, slides another finger inside of her and fuck, she has to breathe, breathe, just breathe. She grips his thigh with her nails and he doesn't even flinch because he's enjoying watching her squirm and she's never given him quite enough credit for how dangerous he can be. She hears it then, some question Chelsea's asking her and she blinks, tries to focus on anything but the way his fingers are curling and twisting inside of her. Shit, she is going to kill him.

"I'm sorry, what?"

"Rick mentioned that Gina wanted you to come to his next signing for publicity. Did you decide if you were going to go?"

Castle's smirking next to her, smirking, and she places her hand over his, stilling him, breathing deeply through her nose. He's flush against her side and he looks so damn smug like he's not trying to get her off in the middle of his bar and if he wants to play she's more than willing . She pushes his palm flat against her, his fingers gliding through her wetness, teasing them both, and she clenches around him, tilts her pelvis down into his hand. He takes in a breath, grabbing his scotch and she smiles as if she's not about a minute away from coming around his fingers.

"I don't know," she replies and her voice is surprisingly steady, years of acting in the interrogation room finally paying off. She turns to him, swallows hard at the fire burning in his eyes. "What do you think, Castle? Would Gina approve of me showing up as Nikki Heat? Or would that be a little awkward considering?"

He looks like he's about to choke on his drink; it's all she needs to rub one hand over his back soothingly, fingers dipping between each ridge of his spine. "What about you?" she asks Chelsea. "Has anyone ever dressed up as Gretchen Lowell for your readings?"

"A couple of fans here or there, but thankfully Black Pawn hasn't forced me into that yet. Then again," she says with a smile, "I don't have a real life inspiration."

Kate almost gasps as he slides another finger inside of her, stretching her apart. She flushes, the moisture between her legs hot and so incredibly intense that if she were to move right now - fuck. She can feel the unraveling in her stomach, muscles clenching around him, the heat setting fire to her veins.

"I'm going to head to the little girl's room and then get a drink," Chelsea says, stepping out of the booth. "Do either of you need anything?"

Castle looks at her, mirth shimmering in his eyes. "Kate? You look a little hot. Do you want water or something?"

She manages a smile, squeezing her legs around his thrusting hand. "No, thank you. I'm okay." She releases a shaky breath when Chelsea finally walks away and turns to him with narrowed eyes, her voice low. "I'm going to kill you."

"Oh, Beckett." He grins, leaning in close. She can smell the alcohol on his breath, the cologne on his skin, her. His finger curl slowly inside of her and she whimpers against his mouth. "Wouldn't it just have been easier to tell me what my present is?"

Four hours earlier...

"Seriously, Castle. Your hair looks fine."

"Fine? No no no, Beckett. Fine will not do." Kate sighs, rolls her eyes. "I'm forty-two -"

"In two days. If I let you live that long."

"Still. I'm forty-two and have a full head of luscious hair. This is a fact that needs to be properly celebrated and displayed."

Kate pushes herself up off the bed, walks over to the open door of the bathroom. Propping her hip against the door frame, she watches him. He looks good. Really really good. His black slacks are slung low on his hips and he's wearing the red shirt he know she loves, the first three buttons open and exposing the thick line of his neck. She loves to dip her tongue into the hollow of his throat, feel the vibrations of his moan against her lips.

"We're going to be late," she chides him gently, her eyes still roaming his body.

"Hey, it's my party. It can't officially start until I get there." He pushes the comb through his hair one more time then stops. Leaning back, he tilts his head to the side and stares at the mirror for a long moment before nodding at his reflection. "Okay, I'm ready."

She stops him in the doorway, hand pressed against his heart. It beats slowly, rhythmically beneath her palm. She kisses him, tastes the fresh wintergreen toothpaste. "You're such a pretty, pretty princess," she teases.

"Does that make you my knight in shining armor?"

"I have saved your ass quite a few times."

Castle slides his palm down the length of her spine, pulls her close. "And yet I've still saved yours more." He traces his tongue over her left clavicle, hums against her skin. "How about we just stay here tonight? You can give me my presents. Naked."

"In the course of the past three weeks, you have sent me over thirty emails telling me how to plan this." She lifts his head from her chest, eyes darkened, and she's so close to giving in, to agreeing to stay. Just the two of them. Alone.

He smiles at her and she's filled with so much warmth. So much desire. "You told me to shut up and to leave you alone."

Kate leans into him, whispering. "Because I throw really good parties." She bites his earlobe, gently. "You can unwrap your presents later but I promise you want to go tonight."

"Ohhh presents! What is it? A pony? A puppy? Oh, Hangover monkey?"

"What's with the animal theme?" She grabs his hand, turning out the lights in the bedroom. "And where would I even purchase a monkey, Castle?"

"You're a detective, I have faith you'd figure it out."

"I didn't buy you a monkey."

"What about you on the bed in nothing but a big red bow covering only your-"

"Seriously?"

"No, I guess there's nothing to unwrap if you're gonna give away the farm." She rolls her eyes, stepping out into the hallway. "Come on, what is it?"

"You're forty-two. I thought this was the year you'd have the answers for all of life's mysteries?"

"I want to be mad, but when you reference things like The Hitchiker's Guide to the Galaxy or comic books you are so damn hot that I can't be anything other than aroused."

Kate smirks. Oh this is going to be fun. "Just you wait, Castle. Just you wait."

He knows he should be slightly ashamed of the streak of pride that zips through his chest when he parks the Ferrari outside the Old Haunt but he just can't be bothered to care. Not tonight. Not when she's sliding out of his car in a scrap of material that barely qualifies as a dress, her long legs on display and her hair loose and free, curls tumbling carelessly over her bare shoulders.

"Stop looking at me like that."

"Like what?"

"Like you want to push me down on the hood of your car," she answers, her body swaying up against him.

"But I do." He reaches down, drags his fingers along her exposed thigh. "Very much. Can that be my present?"

"You seriously want sex on the hood of a car as your birthday present?" She lifts an eyebrow, and he has to smother his smile. She's so cute when she's annoyed. "You're forty-two, Castle, not twenty."

"Can we stop saying my age? It's starting to make me feel old." He leans in and presses a kiss below her ear, her perfume bitter on the tip of his tongue. "If you tell me what my actual present is, I'll stop asking."

"Liar," she breathes, pushing on his chest. "Now, come on. You have an entrance to make."

She leads him down the stairs by the hand and he trips on the last step, his eyes glued to the sway of her hips instead of watching where he's going. She turns around to look at him, amusement dancing in her eyes and he doesn't care how good this party supposedly is because when she moves like that all he can think of is her underneath him, writhing and moaning and he needs to touch her, just -

"Don't you dare," she warns, slapping away the hand going for her hip. "You can behave yourself for a few hours."

"And if I don't will you spank me?" He winks.

"I hate you."

"No," he grins, pulling her flush against him. "You love me."

Kate rakes her nails through his hair, lightly grazing his scalp. "Come on, Birthday Boy. Let's go." He tastes her strawberry lip gloss with the chaste kiss she gives him, one hand sliding down his chest. "Oh and Castle? If you're good, maybe I'll let you spank me."

He sucks in a breath, tries to slow the frantic pounding of his heart as she pulls open the door and tugs him over the threshold. The bar is buzzing, filled to capacity with his family and friends. He spots a few of his colleagues from Black Pawn and has a moment of mild alarm that Gina might be in attendance. He's four chapters behind on the next book and really has no desire to be harangued at his birthday party.

"Did you invite Gina?" His voice is low and panicked and Kate laughs at him.

"Yes but she declined. Said she wouldn't be able to avoid the temptation to verbally abuse you in public."

"Oh, thank goodness." She tugs him forward, her hand soft and warm in his, her hip bumping against his thigh as she leads him toward the bar. "Kate?"

"Yes?"

"Why are all of my employees wearing masks?"

She hands him a menu off of the cherry wood counter. It's different than the ones belonging to the Old Haunt and he glances over the list of drinks. Elektra's Electric Lemonade. J. Jonah Jameson's Jello Shots. Two Face, Shit Faced.

"Oh my God, Beckett. You threw me a heroes and villains party?"

"I told you I was good at this."

Castle wraps an arm around her lower back, drawing her into his body, presses his lips to her neck. "You are officially the best girlfriend ever."

"I can't take all the credit. Alexis was a huge help. Speaking of."

Kate nods her head in the direction of the door. He turns to see his daughter, a whirlwind of fiery red hair dodging through the crowd.

"Dad!" She collides with his side, sending his breath rushing out of his lungs. "Happy birthday."

Castle releases his hold on Kate and wraps both his arms around his daughter. He presses a kiss to her forehead then rests his cheek on her crown, watches Kate smiling at them.

"Thanks, pumpkin. Kate says you helped?"

"Oh, not much. Just helped her with some of the drink ideas and -"

Twisting to face his girlfriend, his giggling daughter still trapped in his arms, he gasps, puts on a face of mock outrage.

"You contributed to the delinquency of my minor?"

"Naming not creating, Dad," Alexis says, her eyes rolling in a near perfect imitation of Kate's. Oh, that's scary. "Hi, Kate."

"Hey, Alexis. Thanks for getting things started. Your dad was-"

"Primping?"

"Basically, yeah." Kate laughs and reaches out to run a hand down his arm, tangling her fingers with his and squeezing. "If you think you can keep the prima donna occupied for a few minutes, I'm going to go check in with Brian and make sure everything is okay."

"I'm standing right here." Castle huffs good-naturedly and leans over to kiss her on the cheek. "And I don't need a babysitter. I can keep myself out of trouble."

"I have five years of evidence to refute that claim," she tosses over her shoulder as she walks away. He watches for a moment, eyes drawn again to the mesmerizing sway of her hips.

"Ew, Dad."

"Right, sorry." He focuses his attention back on Alexis, smoothing back her hair.

"So? Have you figured out the answer to life yet? Are aliens going to attack us? Is the world going to end? Tell me, oh wise master."

"I will have you know, darling daughter, that I still have two days before the answers come to me."

"I'll be eagerly awaiting your call, Fath-" She stops mid sentence, her eyes widening. "Oh god, Dad, she followed me here!"

Castle looks at the sea of people gathering throughout the bar, nodding his head at a couple of other writers. He smiles, gives them a quick wave before trying to locate what has Alexis so freaked out. There's the boys with Jenny and Lanie, some of his editors, and oh- His mother sitting with Jim Beckett. And Captain Gates.

Gates, who hates him even more now that he's dating Kate. Gates, who sizes him up at every opportunity like he's just killed her off in one of his books. Gates, who should not be sitting with his mother and his girlfriend's father telling them about the time he did, well anything, against her command.

"She followed you here?" Castle asks, panicked. "Did you go to the precinct? Why would she come? Is this to torture me?"

"What? No, Dad, my roommate!"

Alexis turns his body until he's staring at a tiny girl huddled in the corner. She's texting, tweeting, facebooking, something while glancing up every few seconds and Castle gives a small wave. The girl nearly panics, burying her head into her neck, typing furiously.

"She seems," Castle pauses, searching for the right words, "like a unique snowflake."

"Obsessed, Dad. She seems obsessed!"

"With you?"

"With you."

Castle bounces back on his feet, grinning. "That's to be expected. I'm awesome."

Alexis rolls her eyes again and it alarms him the number of times both his daughter and girlfriend do that when he's around. "It's not going to be awesome when she comes to the loft to kill you. She was so normal at first, you know? Didn't even know who you were-"

"Hey!"

"So totally not the point right now! But then I come home a month ago and she's reading one of your books. Which okay, that seems fine, but oh my god, Dad, she wouldn't stop talking about you after! She was asking questions about Kate, about how much she was really the inspiration for Nikki and it totally creeped me out! I mentioned that it was your birthday and she must have followed me!"

"Aw, that's cute."

"No, not cute. Creepy." Alexis twists him back around, one hand planted on her hip. "It's seriously freaking me out. I don't know how but she got her hands on one of those stand up cutouts of you. She hid it in her closet at first but now she keeps it in the corner of the room." Alexis shudders, her body shivering exaggeratedly. "It feels like you're watching me all the time."

"Well, I can at least take comfort in the fact that you're not bringing boys back to your room." Castle grins down at her, delighted by the way her face flushes. She's so easy to mess with, his daughter. "What with me watching and all."

"Again, ew. This isn't a joke, Dad. I found her talking to it the other day. Just, like, carrying on a conversation. That's not normal."

"Okay," he concedes, starting to feel a little creeped out himself. "Yeah, that is weird." He looks over his shoulder again and finds the girl staring at him with wide round eyes. "You think it would help if you introduced her to me? You know, take away some of the mystery?"

Alexis tilts her head to the side, considers his words. Castle scans the crowd over her shoulder, looking for Kate, spots her chatting with Lanie and the boys, her face animated with whatever anecdote she's relaying.

"Yeah, okay," Alexis says, drawing his attention back to her. "It's worth a shot. Come on."

He lets Alexis drag him across the bar, nodding hellos to various guests as he goes. They pass the table with his mother, Gates, and Jim and he feels his pulse tick up a few notches, his hands going clammy. Absolutely nothing good can come out of that situation.

Distracted, he bumps into his daughter when she comes to a sudden stop. Castle looks up and sees her glaring at him over her shoulder and shit she looks like a lot like Beckett right now. What is it with the women in his life and those looks?

"Sorry, pumpkin. Got distracted."

Alexis rolls her eyes - seriously, she has to stop doing that - and nods her head toward the mousy girl huddled in the corner, trying desperately to make herself blend in with the wall.

"Dad, this is Shelby, my roommate. Shelby, this is my dad, Richard Castle."

"It's nice to finally meet you, Shelby. I was starting that you were a figment of Alexis' imagination." He gives the girl his best smile, watches in horror as tears spring into her eyes. Shelby stares up into his face for a moment, absolutely silent, then takes off, darting through the crowd and out the front door.

"Well. She seems nice?"

"Oh god, I better go check on her. She really is very sweet and I'm sure she's mortified." Alexis turns to him, her face awash with worry. "Do you mind if I go?"

"Of course not." His heart swells with pride as he pulls her into a hug. He raised a good kid. Though he can admit that it's probably more a result of her innate sense of compassion than his parenting skills. "You're coming for dinner tomorrow night?"

"Wouldn't miss it." She kisses his cheek and smiles at him. "Have a good party, Dad. Don't get too crazy. I don't want to have to dip into my savings to bail you out again."

"Please," he scoffs, walking her toward the door. "My girlfriend is one of the NYPD's finest. No way she'd let me get arrested."

Alexis laughs, her cheeks rosy and blue eyes dancing. "You sure about that?" He pauses, thinks it over for a moment and then shakes his head mutely. "Yeah, that's what I thought. Let's not test your theory, okay?"

"Okay, okay," he grumbles, pulling her into another hug when they reach the exit. "Tomorrow night at eight. Bring a present."

"My smiling face and sparkling personality aren't present enough?"

"Nope. I prefer monetary displays of affection." He lets her go and pulls the door open, grabbing her by the elbow before she can make it over the threshold. "By the way, do you know what Kate got me? I need to know if I should practice my 'This is hideous but I love you so I'm going to pretend to like it anyway' face."

"Even if I did know, why would I tell you?"

"Where is your loyalty, child? Seriously, what'd she get me? A tie? A subscription to People? Patterson's entire collection and a box of matches?"

"Night, Dad. Have fun." She drops another kiss on his cheek then clatters up the stairs, pulling her phone out her pocket as she goes.

"Spoilsport!"

"Was that the roommate who's in love with you?" Kate asks, coming up behind him. She rubs her hand over his back, nails lightly scraping against the material of his shirt.

"Alexis told you about her?"

"She mentioned something about her last night."

Castle turns around, wrapping his arms around her waist. "Did you ever have a cardboard cutout of me in your dorm room, Beckett?"

"Yes," she deadpans. "It's what I learned to shoot a gun on. You're an excellent target."

"You won't tell me my present and you're being mean to me?" Castle pouts. "What's next? You're going to tell me you've become a huge fan of Nicholas Sparks?"

"This jealousy you have of other authors is-"

"Sexy? Endearing?"

"Ridiculous."

Kate's lips touch his ear, her hot breath sliding across his skin. "You have over twenty-five best sellers, Rick. I can't tell you what a turn on that is. I know I don't tell you this enough, but you're brilliant-"

Castle leans back, gripping her shoulders. He raises an eyebrow with an imperceptible shake of his head. "You're being too nice. You have never once called me brilliant. What do you want?"

"You need to head to the table in the back right-"

"You mean the one with my mother, your father and your captain who would probably laugh if I got shot?"

"That's a little dramatic even for you."

"Why did she even come? Oh god, do you think she got me a present? Is anthrax still a thing? Should we scan all the envelopes here?"

"You're impossible. Besides, I'm sure if Gates is too hard on you your mother will step in and defend you."

"You are spewing so much bullshit tonight. I commend you for the effort."

The laugh that comes out of her is light, airy, and fills him so completely. "It'll be fine. If you're good I'll tell you what your present is."

Castle's eyes widen. "Really?"

"No. But you're going over there anyway."

There's a sudden burst of laughter, loud over the people in the bar and array of music, and Castle warily turns his head to the back, right table. The table where his mother is engaged in some kind of story - most likely about him - hand gestures and all. Gates is nearly hysterical and he doesn't like the fact that his mother is teaming up with this woman. He doesn't like that Kate's father is hearing about god only knows what because there was that one time with the cowgirl he met when he was eleven on a weekend getaway to Dallas or the bikini model that he had sneaked into his room at sixteen and he's pretty much about to lose his girlfriend, second job and dignity in the next ninety seconds.

He turns back to Kate, pressing his lips to hers, and oh she feels so good and he's going to miss this. "I love you. No matter what, I love you."

Amusement shimmers in her eyes, flecks of green surrounding the outer rims of brown. "Don't worry, Castle. I'm sure she's not telling them about the time in middle school when she walked in on you fondling your-" Kate's lips lift, dangerously. "Gun."

Fuck. He is so totally and completely dead right now.