A/N: This chapter is M for one very naughty word in the last line, but you could read up to that point and still be 'T' (in case anyone cares).

However, this story will be M for other very naughty reasons in chapters to come. :)

"Seriously, Dad, come on!" Alexis said sighing as she knocked on his door forcefully.

Castle reluctantly snapped out of his daydreaming, grabbed his phone and opened the door to see Alexis, her closed hand still hanging in the air as the door swung away from her.

"Okay, I'm ready!" Castle said shooting her a grin as he breezed past her.

"Jeez, Dad. It takes you longer to get ready than me or Grams and you don't even have to put on make-up! What were you doing in there?" Alexis held up her hand before her father could speak. "Wait. You know what? Nevermind. Don't wanna know."

"Oh, very funny. I was getting ready, that's all. Sometimes looking this good takes a little more effort," Castle said catching his reflection in the mirrored wall decoration and flashing a debonair smile.

Alexis smirked at her father. "Funny… I don't recall you ever taking this long to get ready before you were dating a certain de-tec-tive," she teased, enunciating each syllable as her father pulled her into a quick hug.

"You're probably right about that. But now, I have such competitionKate has an unfair advantage over me because she's so much prettier to begin with…" he joked, looking down at his lovely daughter. "But, I suppose I should be used to being surrounded by such beauty, having lived with you all these years." He paused, giving her an affectionate grin. It never ceased to amaze him that he had somehow managed to raise someone as wonderful as Alexis.

"Oh! And your grandmother too!" Castle's voice sailed up several decibels to make sure Martha would hear in the other room.

"You're safe, Dad. She already left to go meet her friends for dinner," Alexis said shaking her head as she watched him trying to smooth a renegade piece of hair sticking up from his head. "And, by the way, you look very pretty tonight too, Dad. Your girlfriend will be pleased." She paused a beat, a distinctive glint of mischief in her eye befitting the name 'Castle'.

"So… is Kate gonna be wearing her gun to the party again tonight?" She winked at her father and beamed in victory when Castle blushed a little.

Castle squinted at Alexis with a half-smile, a little pride slipping through the disapproval at the mini-jab she had just gotten in on her old man.

"Haha," he said adjusting his tie for the 3rd time in the mirror.

The new couple hadn't yet told anyone that they were officially together with the exception of Alexis, and so by default of course Martha also knew. She told her almost everything after all. Though, technically speaking, they actually hadn't told Alexis about their romance. Recalling what they'd left in the common area of the loft the morning after their rather rambunctious, not to mention exhausting, first night together, Castle knew that they couldn't have exactly kept the relationship from Alexis even if they had tried. While he had remembered to collect Kate's dress and coat from the living room the morning after the charity gala, he somehow had missed her shoes and gun. When Alexis returned later that morning from a friend's and saw the sleek leg gun holster hanging on a chair, she immediately knew that her father had either done something very wrong, or perhaps very right to warrant Kate Beckett's presence that early in the day. The 4 inch dress heels left on the floor had only confirmed that her father and his muse had finally decided to take a page out of one of his books, and she suspected it was page 105 of Heat Wave, to be exact.

Alexis had been very mature about the whole thing, giving the detective her space that morning, only coming out of her room briefly to say 'hi' with a grin from ear-to-ear while Kate and her father had coffee. The realization of Alexis catching her clothed in one of Castle's T-shirts and oversized sweats had made Kate blush more than the thoughts of all the wicked things Castle had done to her naked body the night before.

Castle had approached Alexis to talk about the situation after Kate departed, but Alexis had insisted that they didn't need to have some long drawn out discussion about her father's relationship. "She'll stay over here some, you'll go over to her place… I know how it works, Dad. After all, I've read all your books and helped edit half of them." Castle had cringed a little at that, silently praying that his little girl hadn't picked up too much from his fictional amorous liaisons. Alexis reassured him that she was happy for him and 'more than okay' with him being involved with Kate.

Kate, however, had been mortified at the way Alexis had discovered the new side of their relationship. After much discussion, Kate had decided that it was probably best if she and Castle didn't have any more sleepovers at his place until Alexis had a chance to get used to them as a couple. Therefore, most of their nights together had been spent over at Kate's apartment, for what Alexis euphemistically referred to as "quality time". Even then, Castle didn't always get his way when it came to staying over. That had been the subject of their first disagreement, as a couple at least. Although Castle had come out on the losing side, he was satisfied with the outcome…

"Ka-ate, you're being unreasonable! Alexis will be out late with my mother tonight anyway. And, she's not oblivious to the fact that we sleep together- she's nearly 17," he half-whined to her one night in bed when he ended up at her apartment fairly late. "Besides, she stays overnight with friends all the time. Why shouldn't I get to do the same?" he moped.

"Uh, 'friends' ?" She propped herself up on an elbow next to him, her eyebrows shooting up, hair half covering her face. "I do not let 'friends' do what you just did to me," Kate scoffed at him with a sexy smile. She extracted herself from the tangled sheets and slipped into her robe that had been strewn across the floor, pulling her damp curls back with a clip before sitting back on the edge of the bed.

"And especially not THREE times." She leaned over giving him a light kiss on the mouth.

A roguish smirk crept across his face.

"Uh, technically it was FOUR- sofa…floor NEXT to sofa…shower… and bed," he said sitting up, nodding his head slightly as he named each location on their shared journey to complete physical collapse. "But, who's counting?" he quipped, throwing a devilish grin in her direction, at which she returned a scowl, and then picked up a pillow throwing it playfully, but forcefully at him.

"You are terrible! I am trying to have a discussion with you about how to make this work in a way that makes your teenage daughter comfortable, and all you can think about is how many times you got me off?" She paused and cocked an eyebrow at him. "And, by the way, Castle- it was THREE. I WAS counting," she said matter-of-factly, leaning her head side to side tauntingly.

Castle's grin of triumph instantly fell from his face.

"You… you…" He stuttered with disbelief. "How could you?" He let his body fall back onto the pillows limply.

Kate's expression broke into a stifled laugh. "You're such a drama queen!"

He looked up briefly and shot her a look of dismay, before throwing his arms across his face. "I just… I've never…NO woman has EVER…"

Kate moved closer to him on the bed, crossing her legs Indian style and shaking her head at how theatrical he could be.

"Oh for the love, Rick!" He remained silent and she rolled her eyes as he lay unresponsive on the bed. "Fine, YES, it was FOUR! I was just saying 'three' so you would stop going on…. But, I assure you that at least one woman you've been with has faked…"

She was silenced by Castle's body springing up, and pushing her back onto the bed with surprising speed. He used the weight of his torso to hold her in place, pinning her wrists to the bed next to her head with his hands.

"Castle! What the…Get off of me!" she said with a huff, squirming a bit under him, but not making any real effort to escape. He looked down at her and shook his head, making a 'tsk, tsk' sound with his tongue.

"That was not nice, Detective." He nuzzled her neck with his nose, his lips grazing her skin as he spoke causing Kate to inhale more forcefully than she intended. "You could have caused permanent damage to my male… ego…" His lips continued their trek down to where her robe had fallen down, leaving her collarbone and upper chest exposed. "…but I forgive you."

"Well…" Kate gasped a little as he nipped at the top of her breast with his teeth. "From what I know of your male 'ego', I was sure that you would recover qui-…" He sucked gently on the delicate skin just above her nipple. She paused mid-word, and he could see her jaw muscles clenching in the way that he knew meant she was fighting against the pleasure. Her defiance of what she felt was also quite evident in the way she spoke in short clips. "But seriously…Rick… Alexis… you already… stayed here… last night…"

Castle exhaled in defeat and pulled his weight up, sitting next to her in the bed.

"Fine. You're right. I guess I should leave soon if I'm not going to stay tonight…" he said with a hint of annoyance in his voice, getting off the bed, pulling on his pants and shirt.

Kate sat up and rearranged her robe, watching him tug on his clothes forcefully.

"Oh, come on, Rick. Don't be mad. I just think we should talk about how we want to handle this," Kate said walking over to him, stilling his hands with hers as he buttoned his shirt. She looked up meeting his eyes as she spoke hesitantly.

"I know you've told me that she's 'okay' with everything… and maybe she is, but I think it would be good if we, well… maybe if we spent some time…" Her gaze shifted and Castle's face immediately fell, fearing the words that would come next. Kate paused, obviously thinking intently as she stared at his half open shirt, fingering one of the buttons. "I was hoping… maybe Alexis and I could go to dinner sometime- just the two of us… so she can get to know me as more than the woman who steals her father's favorite sweats, if it's okay with you…"

She didn't get to finish the rest of her sentence because Castle hugged her so tightly that her breath was completely expelled from her lungs.

"Yes!" He released her from his stifling embrace and gave her a quick kiss. "That's a fantastic idea! Maybe after New Years would be good since we're leaving for California next week." He exhaled in relief and smiled at her. "God, I thought you were going to say WE should 'spend some time APART', but no, I mean, YES, I think that would be a great thing to do." He paused half a beat and added, "So now that that's all settled, do I get to stay tonight?" he said raising his eyebrows expectantly and wrapping his arms around her waist.

Kate shook her head at him with her best disapproving look. "You just don't give up, do you?"

"Nope." He pulled her closer. "But… I really do appreciate what you're saying about Alexis, and I actually see your point, to an extent. So, I will begrudgingly leave tonight, BUT, I'm definitely staying over on Friday…"

"Oh, you are, are you?" Kate said, biting the inside of her cheek, amused at his assertion. She placed a delicate kiss on his lips. "Coming over uninvited then, hmm?"

"Uh-huh…" he murmured, brushing his mouth against hers.

"Well, I have other plans…with Lanie…could be late…" she whispered between kisses.

"Well, I'll just wait for you…" he said reluctantly letting her pull away and lead him from the bedroom towards the front door.

Kate paused for half a second and turned, opening the drawer of the desk by the door, turning back to face him with a shiny object dangling on a ring from her index finger.

"Here," she said simply, her hand extended. She shifted her weight anxiously between her feet.

"A key…your apartment? Uh, didn't we just have a pseudo-argument about how you didn't want me over here so much?" Castle said with a hint of confusion on his face, truly surprised at what she was offering him.

"It's not that I don't want you here… of course I want you here. Just give me time to adjust to all of this, okay? I've never dated anyone with a child before, although I realize Alexis is hardly a child really…but, I just… we spend all day together at work-which I love," she added quickly, "…but then if you're over here at my place all the time, or if I start coming to your place… I don't want Alexis to think I'm monopolizing you more than I already do."

Castle watched her intently as she rambled, falling even more in love with her in that moment for showing such concern for his daughter's feelings. "Kate, I can assure you, Alexis doesn't think that…"

"Deep down, I know you're telling me the truth. But I think I'll just feel better about all this when I get to talk with her more one-on-one, you know?" She inhaled deeply, staring at the metal still hanging from her finger. "And as far as the key goes, well, I guess it's my way of saying I want you to stick around for awhile…and, I SUPPOSE you can come over uninvited sometimes…" she glanced up at him with a hopeful look.

Castle stood there, not making a move for the key, stunned at what she was saying to him.

"I mean, if you don't want it…" Kate said hesitantly, starting to pull her hand back.

Castle smiled and grabbed her wrist, removing the key from her finger and squeezing her hand. "Thank you. And I guarantee that if I come over and you're not here yet, I won't snoop around…" He grinned slyly. "Well, not too much, anyway."

He pulled his key ring out and started to attach her key.

Kate leaned in towards him, lifted an eyebrow and whispered, "Snoop here and I guarantee it'll be your last," before she placed one finger under his chin and planted a peck of a kiss on his lips.

"Yep-okay-got it…"

Alexis watched as her father picked up his phone and keys and stood staring at his key ring for a few seconds with a goofy grin before placing them in his suit jacket's inner pocket. The smile remained plastered on his face and Alexis shook her head, trying to recall the last time she had seen him this enamored with a woman and she realized it was probably, well…never.

In theory, Alexis truly liked the idea of her father and the NYPD detective together, although even Alexis realized that most of her knowledge about Kate Beckett came from his stories about their work relationship, of which there was an abundance of course. But, even before the whirlwind romance of the last month, Alexis had sensed a change. She had always known that her father seemed the most happy about work on the days that he got a call from the detective saying that they had a case, and at first, Alexis just attributed this to the fact that her father's depraved addiction to murder was in need of a fix. However, over the last few months, she had picked up on a change when he talked about Kate Beckett. He had more of a twinkle in his eye when he answered her phone calls and Alexis also realized that he seemed to talk less about Detective Beckett, the cop, and more about Kate Beckett, the woman.

For example, he had gone into great detail about her quest for a new apartment and gushed at how 'unbelievably great' Kate was for giving him such honest advice when he had boldly asked her for guidance with Gina. Even when he wasn't trying to, he would often relate whatever conversation topic was at hand back to Kate. It had almost gotten to the point where Alexis felt like pinching him so he would stop pussyfooting around the issue, dump Gina, and ask her out like a normal human being.

He had even made Alexis and Martha travel half way across Manhattan a few months back for Alexis's birthday to try "this fantastic Thai restaurant", which upon further questioning about how he discovered it, he simply replied, 'Kate's favorite' with a nonchalant shrug. A fair amount of conversation over dinner that night had drifted back to 'Kate', as he had started referring to her in front of his daughter and mother. She was hardly ever 'Beckett' anymore, and this less-than-subtle change in name earned more than a few winks between Alexis and Martha throughout the meal.

Alexis glanced at her phone as her father got their coats from the front closet. "Dad, I'm gonna call Ash and let him know we're running a few minutes late. Did you need to call Kate and let her know? We are picking her up before you drop me off at Ashley's, right?"

"Uh, no actually. She texted me and said she was stuck at work later than she thought, so she's just going to meet me there."

Castle frowned as he helped his daughter into her coat. Truth was, he had a sinking feeling that it wasn't just work that was keeping him from picking Kate up to go out. Despite her desire to spend more time with his daughter and the gifting of her apartment key, he knew that she was still apprehensive about taking their relationship public. He couldn't help but feel disappointed that maybe she just wasn't yet ready to arrive at an event together as a couple. Their only ventures out together had been breakfast at Kate's favorite café near her apartment when he stayed over. They really hadn't been out on a true date yet, mostly because work had been occupying both of their schedules for the last several weeks.

"Wow-working this late on New Year's Eve? She really is dedicated," Alexis said casually.

"Yea, she is," Castle sighed, knowing that it was exactly this dedication and passion for her work that had attracted him to Kate in the first place.

Surprisingly, up to this point, work hadn't been a source of too much stress in their lives since crossing the line as a couple. Both had agreed that nothing at the precinct should change just yet, although Castle longed to tell Ryan that he had won the office pool about when they would get together; he had 50 bucks riding on the first week of December. They had slipped back into their familiar banter and teasing without much fuss. Of course, Castle still invaded Kate's personal space every chance he got, but that was nothing out of the ordinary for anyone that had witnessed them interact over the years. The difference was that now, if anyone were to really watch closely, they would see more mutual exchanges of physical contact. For every subtle nudge of Castle's body against hers as they reviewed files and evidence, there was Kate's hand snaking under the desk to find his fingers for a quick squeeze. Castle did appreciate the clandestine courtship in some aspects, for it often times had each of them tingling for the other so badly by the end of the day that it had resulted in some very steamy 'debriefings' when they finally escaped the confines of the precinct.

Alexis and her father made their way downstairs to the waiting limo. Alexis took note of how her father fidgeted with his jacket and tie and adjusted his watch on the short ride to Ashley's parent's apartment.

"Dad, relax. It's just a date. And besides, you already know she likes you," she said giving him a sympathetic pat on the leg.

"That's what I'm afraid of. I don't want to screw this up," Castle answered truthfully as he looked out the window at the lights of the city.

"Well… I'm sure you've had ample opportunities for that over the last few years, so I wouldn't worry about it too much," she said smiling.

"Gee, thanks for your vote of confidence," Castle said wrapping his arm around her as they approached Ashley's building.

"Ash!" Alexis's face lit up instantly as she saw him waiting outside for her and she practically leapt out of the moving vehicle into his arms, leaving the door hanging open.

"Hey, Mr. Castle. Happy New Year," Ashley dipped his head and waved timidly from the curb.

"Happy New Year to you too, Ashley. You two be careful tonight," he said giving them both his best father-knows-best face. "And, Alexis, call or text me when you get to Paige's after dinner so that I know you made it in safely, okay?"

"Dad, yes, I will. Have so much fun tonight!" she said giving her father another embrace.

"I will. Happy…" Castle's voice trailed off as he saw her already arm-in-arm with Ashley and oblivious to the rest of the world.

"… New Year's." Castle felt his lips tugging into a smile at seeing his only child so clearly in love, but he also could not suppress the raw stinging sensation in the back of his throat that reminded him of the first time he had seen her off for overnight camp.

All grown up.

XXXXXXXXXXXXX

As the limo made its way to The Plaza hotel, Castle tried to push away images of his baby girl getting her first New Year's Eve kiss in a few short hours to thoughts of the special night he had ahead of him with Kate. They were attending a special New Year's Eve wine pairing dinner at a restaurant a few blocks from the hotel, put on by one of the top event planning companies in New York City, 'Affair Extraordinaire'. He had been able to swing a last minute table because his publishing company was a top retail client, and Castle himself had spent a fair amount of his own money entertaining with the company throughout the years. The restaurant was small enough to feel intimate, but still would have enough people that he and Kate could blend in to the crowd if that's what she preferred. He had also opted to get a suite at The Plaza due to its proximity and thus avoid the headaches of making it back across town with the rest of the New Year's revelers.

As Castle arrived and made his way through the lush lobby of the hotel, he paused to appreciate the holiday decorations which included a 10 foot tall fresh Christmas tree trimmed exclusively in white lights and various crystal ornaments. The twinkling white lights against the dark green needles reminded him of the New York Public Library decorations and gave him a pleasant memory of the night that he and Kate had experienced so many firsts. He couldn't help the surge of excitement that shot through his body as he recalled the very hot kiss they had shared amongst the live pines brought in for the party.

While waiting in line to check in, he felt his pocket vibrate with a text message and he smiled as he saw it was from her.

Just got home. Traffic = HELL. Where are u?

Waiting at the Plaza to check in.

Sorry I'm running late, I'll be quick.

It's okay, take your time.

He was just about to put the phone back in his pocket when it buzzed again.

While u wait, think about ways I can make it up to you later… *wink*

His eyebrows shot up and the familiar frustration he had felt for the last week made a quick pass through his body, leaving him feel more than a little wound up. Unfortunately, he and Kate hadn't been able to spend any time alone together since his return from the west coast a few days ago. Just after arriving back at her place from the precinct following their gift exchange, Esposito had called to say they had just brought in a suspect on another case who had been on-the-run. Kate and Castle had spent much of the last 36 hours building a case against him and, thankfully, she had gotten a confession earlier that afternoon.

Castle smirked as he texted her back.

Won't be a problem. Had over a WEEK to think about it, remember?

Yes, I KNOW… u remind me every chance u get. ;)

He chuckled a little, imagining her signature eye roll as she typed. He quickly added:

You also know how my creative mind works, so consider yourself warned…

He hoped that message garnered a quick nip of her bottom lip in the way that always had him wanting those teeth and lips to take a crack at him.

Careful…that mouth of yours will get u into trouble.

Castle paused a moment, trying to summon a witty response, but she beat him to it.

But as you've said before, I do LOVE your mouth…

Castle swallowed hard and bobbled his phone a little in his hands as the message came across. He shifted his gaze around the room, suddenly feeling more than a little self-conscious at getting these suggestive texts in the middle of the Plaza lobby. He found himself holding his breath in anticipation. She had never texted like this before.

especially when it's…

He grasped the phone tightly, his heart beginning to race. He was loving this side of her.

SHUT. Ha!

You're still so EASY! Going to get ready. See u in a bit. Xo

He exhaled loudly, his nostrils flaring a bit, and very nearly stomped his foot in aggravation as he stood in the middle of the lobby. He cursed and also loved how she could stoke his fantasies with so little effort. A naughty grin washed across his face as his mind had already shifted to musing about how he would make certain to take her up on her offer and return the favor of teasing her more than a little while he was at it.

A few minutes later he finished checking in and then made his way to the bar, deciding Kate's texting antics had driven him to drink before her arrival. The bar was relatively empty considering it was New Year's Eve. He decided on a Tanqueray martini and called the restaurant to let them know that they would be late and to hold their table. The drink arrived just as he got off the phone and he took a large sip, feeling the pleasant bite of the ice cold gin on his tongue.

Ahh. Now that is what I call a drink.

He settled into the wingback chair, letting his eyes drift shut as he sipped from the chilled glass and made a mental list of all the things he wanted to do to Kate when he finally got her back to the suite that night. He was half way through his drink, and well onto his second fantasy, when a familiar female voice broke the relative silence of the bar.

"Castle? What the hell are you doing here?"

The sip of gin still in his mouth burned his throat and threatened to go shooting out his nose, but somehow he managed to cough it back only to see the figure standing before him through now tearing eyes. He couldn't help but gasp and sputter a bit, not only because his martini had almost offed him, but also because he wasn't sure how to handle this situation or what to say next. At that moment, the only words that came to mind were a steady stream of expletives so, much to the surprise of the woman standing in front of him, he inadvertently inserted a very unconventional word into the customary holiday greeting.

"Well, Happy fucking New Year, Lanie!"

A/N: So, I have to apologize for the long delay, not totally my fault though. Had this chapter 95% finished about a week ago and lost it (stupid MS word and its corrupted files). After a mini-meltdown, several large glasses of wine, and the thought of swearing off computers forever, I rewrote it which is saying alot cause I'm kinda slow. Looking back, this chapter is probably better for the rewrite, although for some reason I'm not 100% satisfied with it still, but I was tired of re-editing.

Lemme know what you think! Next chapter between Lanie and Castle is fun and mostly done... :) -KB