Disclaimer: I don't own Castle, obviously.

A/N: This is the first fanfiction I have ever uploaded (and written!) and I'm a little bit scared but I've gotta take the plunge sometime, right? Eek!

He thinks it's one of his favourite things he's learnt about her since they started this whole thing – her choice of socks, more specifically, her lack of interest in the colour of her socks. For someone who likes control as much as Kate Beckett, he figured it would transpire into every aspect of her life but it's apparent from the orange clad piece of cotton on her left foot and the grey piece on her right that it's not the case.

She's absentmindedly kneading his thigh with her orange and grey clad toes as she watches a documentary that he thinks is about the north pole, maybe the south, he's too distracted by the way her lips keep curling up into this adorable little smile every time a baby penguin comes on the screen, to really take note to what she is actually watching. He has, however, figured out that the narrator is that guy from Doctor Who and it's baffling as to why he's narrating a show about penguins…

"Kate?"

"Hmmm?" Her eyes not moving from the baby penguins for even a second.

"Your socks don't match." He watches the way her brows knit together as she obviously contemplates whether she should ignore his comment and keep watching those penguins she seems to love so much or-

"My socks?" she huffs, toes digging into his thigh for a second, "Castle, why do the colour of my socks matter?"

"They don't, I just think it's cute." He grabs hold her feet before she can pull them away from him.

She glares at him but it's not as convincing as normal considering she's wearing his t-shirt and boxers that he watched her put on 30 minutes ago and is still sporting what can only be described as really, really good sex hair.

"My feet were cold. I wasn't really paying attention to what colour they were," she argues, still glancing back to the TV every few seconds.

"I don't dispute that but I can count at least 8 times in the last few weeks where I've seen you with odd socks… Purple and blue, pink and green, red and navy-"

She cuts him off before he can finish, putting her feet back onto the cushion and away from his hands, "Number one, remembering the colour of my socks, Castle? Creepy. Number two, if it bothers you so much I'll remember to pair my socks up next time."

He leans over and grabs her around the waist, manoeuvring her until she's half on his lap, ignoring her wiggling and half formed protests.

"You know it's my job to notice every single thing about you," ignoring the narrowing of her eyes he continues, "and I like that even though you like control and order, you can be yourself around me. You know, not have your guard up so much" he waves his hands towards her feet, "and I just thought that the odd socks showed that."

He watches the way her eyes soften at his words and feel her lean into him, brushing a kiss against his shoulder.

"Mmm, well, if it's your job to know everything about me I have to sometimes give you somethin' new, huh?" lips still pressed into his shoulder she looks up to his face, "Wanna know something else?"

"Always" he mumbles, quickly kissing the crown of her head.

"Interrupt me again when I'm watching TV and you'll learn something you don't want to know." She glares, eyes still soft and shining with what looks like love before she goes back to watching her beloved penguins.

"Got it. Don't interrupt Beckett when she's watching penguins." He smiles and makes a note to himself to take her to the zoo on their next day off, grinning at the thought of watching her face when she's looking at real life penguins, before shaking his head at how ridiculous he sounds; At how this woman has turned him into a big sap after just one month. He looks down at her, watches her chuckle and push her face into his chest as a penguin pushes another penguin into the water, feels his chest fill up. He's just so grateful she's here with him, letting him see all these quirky, cute sides of herself that just a few months earlier he thought he would never get to see.