Author's Note: This one is a strange relationship set during the time when Alexis is volunteering at the station in season 2. I don't know quite why I like the relationship, but I do for some reason. The sex displayed in the fic is consentual (I can't figure out how to spell that word) between the two participants, but it is shown to be underage sex. Don't read if you have a problem with that kind of thing. Please enjoy the fic.

AUTHOR'S NOTE: UNDERAGE SEX! IS DISPLAYED IN THIS STORY. I KNOW IT IS AGAINST THE LAW! However, this is fanfiction. I would not condone this in reality, however, fanfiction is not about reality it is about fantasy. I know that in canon neither of these two characters would do this, which is why this is no in the episode, this is in the realms of fanfiction. I put out the warning on the front because I know that some people would be offended by the subject matter, the idea was that people would not read it and therefore they wouldn't have to be offended they could just move on.

To the people that have said it was out of character for the characters do this, I refer you to the very name fanfiction. Everything is out of character or out of canon because it is not from the series that we are writing on, it is a fanpiece.

The brunette detective ran her fingers through her hair absent-mindedly, pondering the case that she was currently assigned to, their just seemed to be something strange about it, but for the life of her the detective couldn't work out what and it was slowly driving her insane. The woman slid her chair back, wincing a little at the scrappy noise that it made across the wooden floor before she stood up slowly, arching her back slightly trying to get rid of the kinks that had found their way into her muscles during the time that she had been sitting down. The detective gripped the handle on her mug, winding her way through the empty desks as she made her way towards the break room.

As the brunette made herself a mug of coffee she wondered what her partner's, and partner was a loose word to describe what Castle was doing shadowing her, daughter was doing at the moment. The way that Alexis had been working when she last checked in on her had made it seem like the girl wasn't even half way through the job that she had been assigned for her time at the office, but the little Castle's work ethic was something that Beckett wished her father had because even though there were still piles of boxes and bits of paper, the girl was working hard. Pondering her decision for a moment Beckett sighed, the air being flushed out of her nose quickly turning and grabbing a clean mug from the washboard, running it under the tap quickly and setting up another coffee. As she waited for the little beeper to sound the detective sipped her own coffee, taking in the intense flavour of it and running it over her tongue. The coffee machine dinged loudly once the mug was full prompting the detective to take the mug out from underneath the machine and place two sugars inside it, sweetening the coffee for the younger girl.

No one from the office looked up when the dark haired detective turned the other way – towards the document room – stopping in front of the room for a moment the detective pondered why the door was closed but shrugged her shoulders pressing down on the handle and opening it slowly. When she entered the room the detective softly closed the door behind her, wondering if that was the only way that the younger girl was getting any work done before padding down the little pathway through the filing cabinets towards the desk where the redhead girl had been working before. Still there was no sign of the redhead being there any longer, prompting Beckett to settle both mugs down on the desk and turn around, before looking for where the young Castle could have got up to.

"Alexis?" The woman called out softly but got no reply.

The brunette frowned deeply, a worried gleam coming to her eyes as she looked around the room for the red haired girl. "Where are you?" She whispered to herself softly, peering around the boxes trying to find the redhead. She knew that she was still in the building because Castle was being his normal annoying self and getting in the way of things.

Beckett stood in the middle of the room for another moment before she glanced at the office door that was adjoined to the room, the door was slightly open revealing the fact that the light in the room was on. The detective edged nearer to the door, her footsteps silent on the ground, for some reason the woman didn't call out to the other girl to tell her that she was there, instead she peered through the gap in the doorway.

The detective's trained eyes looked through the gap in the doorway; at first she didn't see anything out of the ordinary about the girl or the way she was sitting in front of the computer. However when she looked closer she could see that the girl wasn't using the computer, but was keeping the same web page open, the girl's bright eyes locked onto the page. The redhead's arm was moving strangely on her lap – Beckett's dark eyes focused in on that movement, her lips pressing together tightly once she processed what exactly it was that the girl was doing.

"No..." The brunette whispered softly under her breath, entranced by the way that Alexis's hand was moving – the way that she could see that pale hand disappearing down into the girl's jeans, the slight bulge that was visible at the crotch and the movement back and forth.

At first the detective didn't know what she was doing, but her body moved her silently through the opened door. The woman closed the door silently even though she released that the other girl was far too gone to realise what was going on around her. Beckett's body moved around the back of the chair that Alexis was sitting on so that she was able to see the pictures that the girl was looking at. A gasp escaped the detective's lips when she realised that it was pictures of her that the young Castle was staring at – pictures from when she was modelling, pictures that showed the detective mostly naked with only thin see through sheets covering her breasts and her hips.

"Kate." The redhead moaned softly, arching her hips up into the pressure of her hand.

Beckett stood for a moment, her eyes widening and a gasp leaving her mouth as she took in the name that the girl had moaned – it was her name. Inside the girl's head it was her that was making her feel that good, it was Kate's hand that was pressing down inside her panties and stroking her just the right way. "Alexis," Kate whispered softly, leaning forward slightly and taking the girl's hand within her own.

Alexis gasped loudly, turning around in the chair suddenly so that she was facing Kate. The brunette took in the look on the girl's face, the way that her cheeks were flushed a light pink and the sweat that was beaded on her forehead. The redhead's bright blue eyes were clouded but locked onto Kate's dark brown orbs.

"Kate..." The girl whimpered softly, trying to get away from the other woman, embarrassment coloured the girl's cheeks, "I didn't... mean for you to hear that..."

Kate leaned forward, her hand slipped up Alexis's forearm until it was at the girl's elbow. The detective kneeled down in front of the other girl bringing her head to the same level as the redhead's as she sat before the older woman leaned forward, eyes locked with the bright blue ones in front of her. It took a handful of seconds for their lips to meet, slowly each of their eyes slid closed until they were absorbed in the darkness, lips sliding over each other.

The brunette moaned at the sweet taste of Alexis's lips, her tongue flicking out over the young girl's lips as she parted her own. The detective prodded gently at the sealed lips of the young Castle, begging silently to be allowed to plunge her tongue inside the girl's mouth. From the way that Alexis had been moaning her name before she knew that the girl wanted her, but she didn't know if it were more than a fantasy that she had and as much as she knew now that she wanted the younger Castle she wasn't going to push her into anything.

Alexis parted her lips slowly, half believing that she was still fantasising, but the taste of Kate's lips was enough for her to believe that it was real. The redhead tangled her free hand in Kate's hair, keeping the woman's head close to her own, their lips pressed together. "Kate..." Alexis moaned softly, her tongue slipping out of her mouth until it was able to run over Kate's.

The brunette pulled away slowly, opening her eyes again until she was staring into the expression blue eyes in front of her, "Beautiful." She whispered softly, slowly using her grip on the young girl's arm to pull her hand out of the loose jeans. The detective brought Alexis's hand up to her lips, keeping their eyes locked as she sucked lightly on the young girl's fingers, wrapping her tongue around the digits cleaning off the girl's essence.

Kate's eyes fluttered at the taste of the younger girl in mouth, prompting the woman to lean forward – Alexis's fingers slipping out of her mouth as she did – to press her lips against the young Castle's again. One of the detective's hands slipped up the tight shirt that clung to the redhead's torso until she was able to cup a bra covered breast in the palm of her hand. Kate could feel the way that the nipple tightened underneath her touch, the tremor that passed through Alexis's body at the shock of pleasure she felt from the brief touch.

The brunette's other hand dipped down into the redhead's jeans, slipping inside the girl's panties. Kate's fingers scraped through the coarse patch of hairs between the girl's thighs until her fingers slipped through wet lips. She could feel just how wet the young girl was, by the way that her fingers slipped on the slick smooth flesh, but her fingers soon found the little nub that she had been looking for.

"Is this alright Alexis?" Kate whispered hotly into the girl's ear as she kissed her skin softly, sucking gently at the patch of skin just under the girl's ear scraping her teeth over it.

"Yes..." Alexis breathlessly replied, her hips rocking softly into Kate's fingers. "Please more please."

Kate smiled softly at the other girl, dipping her fingers into her pussy drawing more of the girl's essence onto her fingers. The brunette rubbed softly at the firm little nub that brought the other girl so much pleasure; Kate scraped her fingernails over the girl's clit.

The detective knew that neither of them had the time to spare with pleasantries, she'd already spent too much time away from her desk as it was, but somehow she didn't want the other girl's first time to be a rushed affair.

The woman slipped her hand out of Alexis's jeans grasping the girl's hips until she was able to lift her just enough to pull the redhead's panties and jeans down to her knees. Kate smiled for a moment, pressing her lips against Alexis's before she dropped down to her knees in front of the girl, kissing along the creamy skin of her thighs towards the girl's pussy lips. Once she met the soft skin with her lips the woman slid her tongue along the drenched folds until she met the hardened bundle of nerves; once there she flicked her tongue over the nub. "You taste so good Alexis." Kate moaned around the girl's clit before sucking it into her mouth.

"Kate..." Alexis moaned quietly, biting down on her bottom lip to keep her moans in as her hips bucked up into the detective's mouth. The way that the brunette was working her clit had the girl clenching her hands inside Kate's hair, keeping the woman's face pressed against her pussy. "Please Kate."

"My pleasure," The detective smirked as she flicked and sucked at the girl's clit, feeling it and the redhead's grip on her hair tighten as she approached orgasm. When the detective knew she was on the edge she bit down lightly on the girl's clit throwing her over, licking up the sweet tasting cum as she did before leaning up and pressing her lips against the flushed redhead's.

"Beautiful." She whispered once again, as her lips pressed to the other girl's firmly, sharing her sweet taste.

"I..." Alexis trailed off, breaking their kiss to look into Kate's eyes, "Thank you, that was... perfect."

"My pleasure," The detective replied, kissing the redhead soundly again, "Just please don't tell anyone, especially your father, he'd kill me."

"Deal," The redhead grinned, "What does this mean for us...?"

The question hung in the air for a moment before the brunette just shrugged. "We'll see where it goes."

Alexis blushed a fierce shade of red at the detective's words before grinning as she threw her arms around the other woman and held her tightly, pressing her lips against the brunette's.