Disclaimer: I don't own Castle. The only profit being made is my own amusement (and hopefully yours).
December
"Why, Detective Beckett," he teases, as she's lying blissfully exhausted in his arms for the first time, "I never guessed you'd be so talented."
This earns him a gentle punch on the bicep. He remembers a time he saw Alexis swatting at Ashley the same way, and then he remembers how meeting Ashley's parents was such a huge step in his daughter's relationship. He kisses Beckett's forehead and, trying to sound as casual as if he were suggesting a movie and popcorn, asks, "So are we going to your dad's for Christmas?"
Beckett's content expression instantly turns into a nervous one, and she scoots away from him and pulls the covers up to her chest. "He's fixing up his place, so it's probably a mess."
"We could invite him here to meet Mother and Alexis."
"I don't think he likes huge gatherings."
"Five people is not huge," he points out. "And I thought you said your new year's resolution was going to be spending more time with your dad."
"It isn't the new year yet, is it, Castle?"
Directness has worked for him lately with her, so he tries it again. "No, but I thought we could get an early start. You know, introduce us and everything."
She looks down, her fingers tracing the wrinkles in the sheets, and shrugs but doesn't say anything in response. He knows what this is about; it's about the trust that he's spent months trying to build with her, the trust he's still not sure he's earned. "Look," he tells her, "I know you don't want to do the whole meet-the-parents thing because you're still afraid I'll leave you when the next pretty girl comes around."
Her hands pause in midair; it tells him that he's perfectly put her doubts into words.
"I can't make you any promises," he continues. "No one can. Sure, I've screwed up before, but I know why I screwed up, and I'm going to try my best to not let it happen again. But you need to try too. You need to give me a chance."
She doesn't appear completely convinced, but she does take a deep breath and meet his eyes at last. "Okay. I'll call him today."
As they lie there in silence, he marvels at how much progress they've made in the past twelve months and contemplates how much work they'll have to do in the coming weeks and years—no, the coming lifetime.
She soon begins speaking again. "So I never got around to asking you. What's your new year's resolution?"
He reaches out a hand and entwines her fingers in his. "I don't know. Start a pool on Lanie and Esposito, because we know something's going on or about to." (She grins and high-fives him with her free hand in response.) "Write more steamy love scenes in the next Nikki Heat novel." (She rolls her eyes but she's still smiling.) "Stop checking in with Alexis every three hours." (Laughter.) "Show you how much I love you."
"Hmm," she murmurs. And Kate Beckett is usually not one to play cute-and-coy, so it's completely adorable when she raises an eyebrow and singsongs, "And just how much do you love me?"
He leans over, presses his lips against her earlobe, and whispers, "You have no idea."
FIN.
Author's note: The story is complete as is, but there is an epilogue to follow. As someone who wishes that the epilogue of Harry Potter never ever happened, I thought I'd give you fair warning: fluff and nonsense ahead.