Author's Note: Thank you all for another lovely year of keeping Caskett alive. :) I wasn't going to do a Christmas story this year, but this bit of utter silliness somehow happened nevertheless.

"Kaf'rin Beckett! You got some 'splainin' to do!"

Kate flinched, startled out of what she had been doing as the angry voice rang out through the loft, accompanied by the stomping of small feet on stairs. Tiny arms were folded forbiddingly over a tiny chest, and two little blue eyes were narrowed in accusation.

"Lily!" Kate exclaimed, shooting an anxious glance at the man beside her. For an instant, Captain Beckett, fearless commander of the NYPD's 12th Precinct and veteran of hundreds of homicide cases, almost felt cowed - like a guilty teenager caught in the act of rebellion.

But then she rallied, summoning a narrow-eyed glare of her own. "You're supposed to be in bed."

"You're 'upposed to not be kissin' Santa!" her daughter retorted angrily, reaching the bottom of the stairs and advancing across the room toward the transgressors, a fearsome scowl twisting her features. "On'y kissin' Daddy! Not Santa!" she repeated for emphasis.

Kate swallowed, looking sideways again at the tall man in the red suit and bushy white beard. "Well, I-"

"Hey, Lily," the man interrupted, his eyes twinkling at the child as he surreptitiously shoved the sprig of mistletoe into his pocket. He lowered his voice to a stage-whisper and asked, "Can I tell you a secret?"

The little girl's expression didn't budge, but she took a step closer. Lily Castle couldn't resist a secret.

"What secret?" she asked suspiciously. The man in the red suit dropped into a crouch, gesturing her closer. Lily cast a quick look up at her mother, who nodded encouragingly. She took another step, and another.

"Don't get mad, okay," the man said earnestly, "but the thing is, see, I'm not really Santa."

"You're not?" The child peered at his face, her anger subsumed by curiosity. "You yook jus' yike him."

"I know." The man nodded. "See, Santa let me borrow his costu - uh, I mean, his suit. His clothes. Because he's so busy tonight, you know? Delivering allllll those toys to all the kids everywhere?"

"It takes allllll night," Lily put in with a wise nod. Kate bit the inside of her cheek, struggling to keep a straight face.

"Yeah, it takes all night," the man agreed. "So Santa was too busy to read stories to the sick kids at the hospital. So I said, let me have your red suit, and I'll go read the stories to them. Okay?"

He reached up to his face, moving very slowly, making sure that Lily was watching. She was. Her bright blue eyes were riveted as he detached the fake beard and carefully peeled it away.

The loud, dramatic gasp that escaped Lily's lips almost made Kate choke on her own tongue. Oh, how she wished she'd had her phone out to capture that moment. She bit her lip, hard, and stifled the laughter that bubbled up her throat.

"Daddy?" the little girl breathed, her expression a picture of pure astonishment.

"It's me, sweet pea," he confirmed, holding out his arms for a hug. Lily melted into him, but immediately pulled back, a strange look on her face.

"Dat your belly?" she asked in confusion, patting his midsection. He grinned, ruffling her hair with one hand.

"It's a pretend belly, sweetheart. Daddy's not quite as chubby as the real Santa, is he?"

Lily shook her head, but her little face was scrunched up in thought. Kate hastened to intervene before her daughter's clever mind could start making connections.

"Come on, little flower, let's get you back to bed," she said, lifting the child onto her hip. "Daddy will be up in a minute to tuck you back in."

Her husband took the hint, swiftly disappearing into his bedroom as Kate went up the stairs. The righteous indignation that had sustained Lily through her dramatic entrance gave way to exhaustion, the little girl slumping bonelessly on her mother's shoulder. It had been difficult to get her to sleep a couple of hours ago, the excitement of Christmas Eve making her manic, but this time there was barely a peep as Kate settled her daughter back into bed, pulling up the covers over her slender shoulders.

"Sleep, baby. Santa can't come deliver your presents until you're asleep," she murmured. Lily's eyes were already closed, her breathing beginning to even out as Kate brushed a kiss to her forehead and withdrew.

Castle appeared in the doorway, having hastily divested himself of the top part of the Santa costume - the wig, hat, coat, and fake stomach - though he still wore the red pants and shiny black boots. "Out already?" he whispered.

"Hopefully for good this time," she whispered back. He nodded, slipping into the room to place his own kiss on their daughter's pudgy cheek before they both slipped back out again, pulling the door shut and moving quietly back down the stairs.

"Good save there, Santa," Beckett commented as they reached the living room. "That was a close one." She glared at him, adding, "If someone hadn't been so eager to take advantage of the mistletoe..."

"How was I to know she'd wake up?" Castle protested. "Anyway, I didn't hear you complaining about a little Santa / Mrs. Claus roleplay," he added with a smirk.

Beckett huffed, a slight flush spreading across her face, but she couldn't deny it. "Well, let's just hope she doesn't start thinking too hard and figure out where the presents really come from."

"Yeah, she's much too young for that!" he agreed. "If we're lucky, she'll just think it was all a dream or something." He paused, thoughtful. "Although, if she really believes that I know Santa personally, that would definitely be an asset for my cool dad status."

"Your cool dad status doesn't need any help," Kate replied with a roll of her eyes. "She already thinks you hung the moon. I'm the one who's in trouble here, if she remembers catching me kissing some strange guy!"

"True," he mused with a twinkle in his eye. "You certainly were in the doghouse for a minute there. Good thing your favorite writer was here to save the day."

"Yeah... I'm off the hook for now, but just wait until she finds out what Santa's already brought her for next year."

"What do you mean?" Castle asked, frowning, bemused, as a slow smile crept over his wife's face. "Kate?"

"There's one present you have to open tonight, babe," she murmured, catching his hand in hers as she moved past him toward the mantelpiece and the enormous tree, sparkling with garlands and ornaments and twinkling colored lights.

Kate plucked a small box from the huge pile of festively wrapped gifts underneath the tree, and turned back toward Rick, pressing it into his hand. "I know your family tradition is to open all the gifts together on Christmas Day, but this one doesn't need an audience," she said, biting her lip, lifting her eyes to his face.

He cocked his head to one side, still confused. "Um, okay..." Her soft smile seemed to reassure him, and he shifted his attention to the gift in his hands. Quickly he undid the ribbon and lifted the lid.

"Kate," he gasped when the top came off the box, revealing a slim white plastic stick with two pink lines on it. "Oh my god. Really?" He looked from the box to his wife's face, shining now with a wide, full smile as she nodded confirmation.

"We're gonna need another stocking next year," she said, and then let out a squeak as her husband swept her up into a bear hug, both of them laughing as the gift box hit the floor.

"Another baby!" Castle exclaimed in delight. "Oh my god, best present ever." He peppered kisses all over Beckett's face until she huffed and grabbed his ears, bringing his mouth to hers for a proper kiss.

"Did you see the doctor? What did she say?" he asked when they came up for air.

Kate shook her head. "I have an appointment next week, after the New Year. We can go while Lily's at preschool. I knew you wouldn't want to miss it."

"You're the best." He kissed her again, and again, his broad palm settling over her still-flat abdomen, a reverent caress. "God, I love you."

"I love you too," she smiled against his lips, "but now that Lily's back to sleep, we better get to work, babe." She patted his chest and then slipped out of his arms, tugging him toward the laundry room where the remaining gifts were hidden. "Come on, we've got a lot of stockings to stuff."

"I'd rather stuff-"


He chuckled, sliding his arm around her waist and falling into step beside her. "Okay, okay. Back to work. I never knew Mrs. Claus was such a taskmaster."

Kate smirked and arched an eyebrow at him as they moved across the room. "Oh, don't worry. After we get all the presents into place, there might just be something else for you to unwrap."

"Ho, ho, ho!" Castle pronounced with a wide grin on his face and a twinkle in his eye. "And to all a good night."

Thanks for reading! It's probably totally obvious, but this bit of fluff was inspired by the song "I Saw Mommy Kissing Santa Claus."

To all who celebrate Christmas, I hope you have a lovely holiday this year.