A/N: So first of all the obligatory, I don't own Castle or anything about it. I'm just borrowing a couple of their characters.

Second, a warning. This story is going to have probably 3-4 total chapters but is still made up of way more smut than plot. It's rated M for a reason and if that isn't your cup of tea then you probably won't like this and it would be in your best interest to leave at this time.

For everyone who is still with me, let's have a little foray into what could have happened back in season 2 when Beckett is living with Castle after her apartment is blown up. The next chapters should follow this one shortly, but I'd still love to hear back from all of you if you're so inclined while I'm working on them.

The first time it happened was an unexpected accident. Beckett had been living at the loft with Castle since her own apartment had blown up a few days before. It had been easier than she'd expected. Living with Castle and his family. She would have expected to miss the privacy and solitude she'd become accustomed to, but it was actually nice to come home to a group of people that cared about her. She hadn't had a true family since she was 19.

She had gone out for a coffee with Lanie on one of her days off, leaving Castle to work on his novel in peace while Martha and Alexis are at some kind of retreat for the weekend. Castle had sent them off after the stress of the case the week before. He'd offered to send her as well but she'd declined. No way could she let Castle pay to send her away to be pampered at a spa for an entire weekend.

No, she'd remained in the city but was trying to make herself scarce so that Castle could attend to his writing obligations.

She quietly let herself in with the key he'd given her, kicking her boots off in the hallway closet and making her way further into the loft. An unidentifiable noise came from the direction of Castle's office through the bookshelves that blocked him off from the rest of the open main floor.

Beckett had to admit that she was curious about his writing process. He was her favorite author after all, even if he was now her partner too. She remained quiet as she approached his office, not wanting to distract the man who was presumably hard at work. But what she saw when she reached the doorway made her stop in her tracks.

Castle was there, sitting in his office chair, at his desk, with his laptop open in front of him. That's not what caused her jaw to drop and her eyes to widen. He was sitting side on to the doorway which gave her the perfect view of his hard erection in his hand as he jerked off. The noise came again and she realized with a start that he was watching porn.

She couldn't see the screen but could hear the soft moans and grunts issuing from the speakers of his laptop even as she couldn't tear her gaze away from his manhood protruding proudly upwards. The tip glistening with precum that was quickly whisked away by his hand and spread down his shaft.

A twinge below her stomach showed her own body's approval of the sight before her as arousal flooded her system. Her mouth watered at the sight of him fisting his cock, his hand sliding easily up and down in a well-practiced motion.

He was speeding up, a grunt escaping his lips as his hips rocked in a slight counterpoint to the movement of the hand gripping his shaft and sliding over the head.

He was going to cum and he was going to realize that she'd seen him as soon as he did and turned away from the screen before him. She had to go.

Beckett used all of her self-control to tear her gaze away from the man before her and force her feet to carry her quietly towards the stairs. But there was nothing she could do to remove the things she had seen from her mind. Castle was well endowed, that much was undeniable. Apparently he hadn't been exaggerating all this time as she suspected he might be. No, he had the proof to back up his claims and she'd now seen it for herself.

Her feet carried her up the stairs and into the guest room where she had been spending her nights.

Castle was alone. He'd sent his mother and daughter off for the weekend and Beckett had gone out for coffee with Lanie. He was meant to be writing. In fact, he had been writing. That was the problem. He was in the middle of writing a sex scene between Nikki and Rook. They had finally made up after the events of Heat Wave and were now consummating their new relationship, but he couldn't get the images of it being himself and Beckett tangled up among the sheets instead of their alter egos. It didn't help that she was currently living with him either.

He decided to take advantage of his time alone and saved the abysmal progress he'd made on Naked Heat, oh she was going to hate that title, in favor of his favorite porn website. He browsed the top videos for a few minutes trying to find the right video before settling on a simple clip of a long-legged blond and a tall, dark haired man. Just what he needed to get his mind off a certain brunette detective.

He released his already semi erect member as the video began and it wasn't long before he was pumping his shaft, engrossed in the couple before him. He fought to keep his mind on the screen instead of the woman of his imagination. He was definitely imagining it was the blond actress on her knees before him with her lips wrapped around his length instead of Kate Beckett. The scene moved on and soon he was inside of her, thrusting his hips in time with the man on camera, but now he couldn't see her face. Just that amazing body that reminded him so much of the quick flash he'd seen when he had rescued Beckett from her burning apartment.

He couldn't hold back any longer. He gave in to his imagination. Seeing himself in the dark-haired man and his gorgeous partner in the woman rutting desperately together was all it took for him to blow his load. He slumped back against his seat, still slowly sliding his hand along his length until he begins to soften.

Castle sighed in disgust when he looks down and realizes he's made a mess like an over excited teenage boy. Shutting down what's left of the video he hoisted himself from his chair and headed towards the shower, shucking his soiled clothing as he goes.

He emerged a few minutes later from the now steam filled bathroom cleansed of all evidence of what he had done. After redressing, he decides to go get take-out for dinner for Beckett and himself. He's well aware of what she likes by now and should be returning soon.

He crosses the loft to the front hall closet to grab his coat, but comes up short when he nearly trips over a pair of boots just inside the doorway. With a jolt, he realizes that Beckett has already returned home. Home?

He heaved a sigh of relief. She must have just gotten back while he was in the shower. It's a good thing he hadn't taken any longer to finish than he had or they both would have been in for a rude awakening.

Changing his path, he decides to go see if there's anything special she's in the mood for tonight and heads towards the stairs.

Arriving at the top, he realizes that her door is shut. That's strange, she's usually got it open. He's found himself amazed more than once about how well she has fit in with his family and hasn't closed herself off from them yet.

But now she has her door closed and it gives him pause. He knocks softly and calls her name. No answer. He steps closer to the door, pressing his ear against the wood and realizes why she wasn't answering him. He can hear the shower running. She must have wanted to clean up before dinner.

He hesitates, hand on the doorknob, before turning it and pushing the door open. There's a second door between her room and the connected bathroom. He can talk to her through that without invading her privacy. Or so he believes.

Castle enters the bedroom, taking stock of the fact that Beckett is nowhere to be seen which means she is, indeed, in the shower. The sound of which is much more evident now that there's one less barrier blocking it.

Oh, shit. There is also one less barrier than he expected. As Castle turns towards the ensuite he realizes he's made a mistake. Beckett didn't shut the bathroom door. He turns to go. He'll just take a guess.

As he makes to turn away, he's stopped by the realization that he can see Beckett's silhouetted body through the white shower curtain. He can't help but stare at her feminine curves. Such a tantalizing sight that doesn't let him see quite enough.

Castle watches as she runs her hands over her body, presumably covering every inch of it with soap suds from a cloth that he can't see and he feels a renewed stirring in his groin.

A stirring that turns to a full-on erection when her hands pause at her waist and don't reappear. He can't tell if she's facing towards or away from him, but the spreading of her legs is obvious.

He can imagine it all too well. The way her fingertips must be parting her slick folds, questing for that spot.

The soft moan emanating from the bathroom tells him she's found it.

He can see it now. The way she would be circling her clit. Teasing herself under the hot spray of water. How she abandons her clit to work her way lower, pressing a single slender finger against her entrance and then pushing it inside. How she works herself expertly, adding a second finger to the first and grinding down against her palm.

He's so engrossed in his own interpretation of what is happening on the other side of the curtain that he almost doesn't realize that the real Beckett is reaching out. He can see the shadow of her hand and arm as she stretches upwards and grasps the removable shower head from the bracket on the wall.

Castle nearly makes another mess when he sees the spray of water splashing against the smooth lines of her pert breasts, her stomach, her thighs. She's now standing side on to him and he can easily see how she hitches her leg up onto the seat on the shower wall and aims the spray from the showerhead towards the apex of her thighs.

He mentally blesses his own forethought to place a light in the shower stall which provides the backlight that allows him to see her silhouetted form.

A louder groan issues from the semi hidden woman now and he watches her press her hips forwards, questing for the source of the pressure that's now pounding against her core. Slicing through her folds to reach the sensitive nub.

"Rick" A breathy sigh reaches his ears and he jumps guiltily assuming he's been caught out. But Beckett doesn't stop. She hasn't noticed him at all.

He realizes what's happening when she calls out his name a second time. This time his surname in that same breathy, aroused voice. She's getting off to the thought of him.

He has no idea what scene she's imagining but there's no doubt in his mind that Kate Beckett is masturbating to the thought of him, much the same as he'd been doing not long before. It doesn't occur to him that she may have seen him doing just that.

Deciding that he needs another shower, right now, Castle backs out of the room and gently closes the door. He's now sporting a raging erection that is demanding his attention and he can't risk attending to it in her bedroom. Instead, he rushes for the solitude of his own bathroom where he can rub one out to the memory of Kate calling his name. And then, he can come up with a plan.