A/N: I've been reading The Lover's Dictionary by David Levithan the past few days and it kept making me think of Castle and Beckett, so this kind of happened. A C/B version of the book, if you will. I'm not sure how many of them I'll do, but I have ideas for at least a handful of them (hopefully!). All italics at the top of each chapter are excerpts from the book and were not written by me.

Beguile, v.

It's when you walk around the apartment in my boxers when you don't know I'm awake.
And then that grin, when you do know I'm awake.
You spend so much time in the morning making sure every hair is in place.
But I have to tell you: I like it most like this, haphazard, sleep-strewn, disarrayed.

She never brings pajamas.

Work pants, sweaters, jackets, impossibly high heels, sure. A section of her duffle bag specially marked for delicate under things, things with which to torture him long after she gets home from work, but never, ever pajamas.

The first time she steals one of his tshirts and a pair of boxers and slides under the covers and into his side, Castle is sure she's going to call him out for the giant grin on his face. He can't help it though, the easy way with which she rummaged through his drawers, the sight of his things on her body, everything about it so domestic and familiar, he can't quite believe it's happening. She doesn't though, doesn't roll her eyes or poke his cheek or bite his shoulder for being sappy, so he just winds an arm around her and pulls her close, inhaling the strange new mixture of him and her draped all around them.

His hand finds its way underneath the hem of his own well worn cotton, wrapping around her hip, and then she's sliding a leg against his and dropping off already, the heavy sigh of her sleepy lungs exhaling against his neck.

He likes it.

She keeps doing it.

Months go by and they don't always go into the precinct together in the morning. Sometimes she likes to go in early to do paperwork or play catch up on "all the things he distracts her from", rising so early that half the time Castle doesn't even feel her getting out of bed. The other half of the time, he pretends he doesn't hear her and watches through sleepy lids as she softly walks her way around his bedroom in the low light from the half open bathroom door, getting ready as quietly as she can.

These moments are his favorite, though he hasn't really had the opportunity to share that with her, often wonders if it'll ruin it the second he does. Her hair is rumpled, still half curly from the day before, but usually pulled up in a messy bun as she bends over in her duffle bag for her clothes for the day, all long, toned legs coming out from under his shorts. On this particular morning, the shirt she's wearing, one of her favorites (he washes it more times a week than any of the clothes he actually wears, just so she can use it whenever she wants), is half tucked in to the waistband of her boxers and he can see a sliver of tan stomach that makes even his 5am brain run a little hot.

She sighs as she thrusts her hand farther into the bag, clearly looking for something she can't find, brows coming together in a frustratingly adorable pout as he quietly tucks his pillow farther under his own cheek so he can see her more clearly. The expression on her face, framed by her haphazard hair and deep morning shadows makes him want to get up and write, maybe allow Jameson Rook one of these moments on an early morning, but he's too selfish to get up and intrude on what he's watching.

Beckett eventually finds what she's looking for, a shirt, he thinks, and then she's padding barefoot into the bathroom with an armful of the stylish armor she wears to work every day.

Castle slips in and out of consciousness as she showers, he hears the low groan of the faucet, the sharp sound of water on tile, and then it's all slightly muted as she presumably steps under the spray. He has one of those waking dreams of her washing her hair as he watches her, his own fingers gently sliding through hers as they lather up the shampoo together, as he presses his face into her water warmed neck and sucks lazily, brain still foggy with sleep, but he wants her always.

He wakes again when he hears the soft pop of the bathroom door. She likes to open it after her shower because it gets too humid, the scalding water she uses fogging up all of the mirrors in seconds, but he's glad because he can see her again. She does her makeup, dries her hair, surveys herself in his mirror, in his bathroom, in his bedroom, in his life. Well, possibly just in his mirror, but in the sleepy haze of morning, everything carries more meaning for him, and he can't help but assign this a milestone of some kind.

Kate Beckett Does Domestic Things in His Bathroom. It's a mid level kind of milestone, somewhere between sleeping over and moving in, but it feels important enough to note so he does. Repeatedly. He is nothing if not thorough, after all.

(Just ask her.)

When she finally does emerge, she tosses her sleep clothes (his sleep clothes? their sleep clothes?) into his laundry hamper, and sweeps down for her shoes. This means she's about to leave, which makes Castle want to reach out for her, snag a wrist and pull her back into bed and make her stay with murmured pleas of how lonely he is when she goes into work without him or how cold he is all alone in his bed, but on this particular morning, he doesn't need to because she's walking over to his side of the bed before heading out the door, and she's kind of grinning a little bit.

"See you later, Castle," she whispers softly to him, dragging her smiling lips across his cheek as she lets one hand slide around the back of his head briefly, holding his face to hers for a moment before releasing him to back her way out of the room.

He's not sure how long she's been aware of his wakefulness, if she's always aware of it, or just happened to catch his open eyes this morning, but the thought of her enjoying this little morning routine as much as he does leaves him feeling warm and happy and content.

He wonders if it's a milestone for her too.