"Now, you're sure you don't mind staying with her tonight?" Kate asks for probably the eighth time since opening the door just a few minutes earlier.
Alexis grins, nodding again. She sets her bag on the table behind the couch, but thinks better of leaving it within reach of curious hands and moves it to the breakfast bar. Her baby sister is too inquisitive for her own good; it's best to remove things from temptation.
"I'm sure, Kate. You and Dad haven't been out without Lily in forever. You need to leave the house for something other than work and doctor's appointments."
Kate Beckett huffs, but doesn't refute her claims. Everybody knows they've been sticking close to home, and everyone knows why, but they still deserve a night to let their worries go and relax.
"So," Alexis continues, "you're going to go and have fun that doesn't involve blocks, plastic playsets, or cartoon singalongs, and Lily and I will see you in the morning."
"Fine, fine. Try to make sure we're not imposing and you mock me. See if I'm considerate of your schedule next time," she grumbles, tongue in her cheek. "And we go out plenty, you know."
"Sure you do," Alexis says, looking around the room. "Where is Lily anyway? And Dad?"
Kate's eyes lift toward the ceiling. "The dynamic duo is working on getting hardened chunks of homemade playdough out of your sister's hair."
"Oh yes," Beckett drawls. "Turns out that, while it is safe and natural, the stuff also effectively becomes plaster if you tweak the mixture enough. And tweak the mixture your father and sister did. And then your sister decided to slather it over her head. They've been up there a while."
Thankfully, Kate doesn't seem bothered by her laughter.
"Why don't I go help them?" Alexis suggests. "That way maybe Dad can come down and get ready, and you guys can get out of here sooner."
Kate chuckles. "Thanks, Alexis."
She grins over her shoulder, making her way upstairs. Her father's low voice guides her down the hall toward the bathroom, and her giggling sister's splashes are enough to tell her they're still working on cleaning up.
"Hey, mad scientists," she says, stepping into the bathroom. "I hear you might have discovered a new and improved formula for concrete."
"Lexi!" Lily squeals, all but flinging herself over the side of the tub to get to Alexis. "Daddy, no." She swats at Castle's confining hands.
"Lily, yes," their father says, easing the three-year-old back down. "We're not done yet, sprout. Alexis will be here all night, but you still have half a head of playdough."
"And slightly pink hair," Alexis observes, stooping to press kisses to both of their cheeks. She grins at her father's look; someone's not as amused as she is. "Relax, Dad. I'll finish up here; you go change and get ready for your date."
Her father glances toward his wrist, groans at the time. "We are so late, aren't we?"
"You'll be fine," she assures. "Kate's already ready - and she looks fantastic, by the way - so you should go make yourself pretty. I'll take care of this crazy girl."
She nudges her dad out of the way before he can protest, rolling up her sleeves and sinking to her knees in front of the bathtub.
"Hi," Lily chirps, cheerful despite the fact that Alexis takes over for their father in reaching for a large clump of bright pink playdough-turned-plaster hanging from her hair.
"Hi, Lily bug. It looks like you had fun today."
Lily grins, wiggling under her hands. "Ya. So much fun."
Alexis nods, working the chunk free from her sister's hair and moving onto the next one. Her dad made good progress, but wow, there's still a lot in Lily's hair.
"Did Mommy have the day off today?"
Her sister nods, beaming at the reminder. "Uh huh. Mommy stayed at home today and we pwayed so much. Me, an' Mommy, an' Daddy."
"You did, huh? What'd you play?"
Lily's happy to fill her in on everything they'd done that day, complete with a seated reenactment of the spontaneous dance party her father had initiated. Alexis laughs, wiggling her fingers against her sister's belly.
"You're so crazy. Our silly Lily," she singsongs, managing to blow a raspberry on Lily's cheek while her sister giggles.
"Daddy's sillier. That's what Mommy said. Mommy said 'Babe, you're a wunatic,' and Daddy said he knowed."
Bracing herself on the tub, Alexis laughs. That sounds like Kate. And her father, too. "What made you put this in your hair, huh?" she asks, changing the subject.
The answer doesn't surprise her in the slightest; with an imagination as wide as the sky, Lily is every bit her father's daughter. She would decide to play pretend with what she had at hand.
"Crazy girl, we can't play hair salon with playdough," Alexis tells her, tapping her chin.
Lily's answering look has her biting her lip to contain her laughter. It's one part defiant 'why not?' and one part 'yes, I know that now,' and every bit inherited from Kate Beckett.
"Tell you what, Lily bug," Alexis begins, combing Lily's hair back from her forehead, feeling for more playdough chunks in the process. "I will call Gram, and next week we'll have a salon day at home. But you have to promise me you won't use your playdough as hair gel again. Okay?"
Her sister's mouth drops open, her nod coming a moment later. "I lub that."
"Me too. You promise?"
"Uh huh! No more, Lexi, I pwomise."
Alexis smiles. "Good girl," she says, reaching for the shampoo, ignoring her baby sister's whine of protest when she begins to lather the girl's hair. "We're going to have so much fun tonight, aren't we? It's sister night."
Lily's face brightens. "Sissy night's the best!"
"I think so, too," Alexis whispers, dropping her forehead to her sister's, ignoring the fact that she's likely going to come away with a soapy hairline. After a moment, she speaks again, "Okay, let's rinse and get you into some comfy clothes."
Once the girl is dried and dressed, Alexis allows Lily to lead her by the hand down the stairs to the main floor. Kate smiles from the chair closest to the office, accepting Lily's enthusiastic half-tackle with a quiet oomph.
"All clean?" she asks, checking her daughter's hair for herself. Satisfied, she dips her head, rubbing her nose in the curve of Lily's neck.
"All clean," Alexis confirms, sinking onto the couch. "And ready for our super fun sister night."
She winks when Kate lifts her head again; they both know distraction will be the key to everyone's plans going smoothly, but it kind of remains to be seen whether it'll be for Lily's sake or not.
"Perfect," Beckett murmurs, pressing a kiss to Lily's head. "Sister night sounds like so much fun. What are you going to do?"
"Pway games. Watch a movie," Lily says before Alexis can.
Kate nods, wrapping her arms around Lily, her squeeze firm. "Well, in that case, we better see if Daddy's almost ready, so we can get out of your hair."
Lily giggles, rubbing her head against her mother's chin. "Babe!" she yells, dissolving into giggles at Kate's surprised expression.
"Hey, that's what I call Daddy, crazy girl," she says, tickling Lily's belly.
"S'his name," Lily says, yelling for her father again.
Kate and Alexis chuckle together.
"No, baby," Kate says. Her fingers slip up her daughter's side. "His name is Rick. Babe's just something I like to call him, but it's not his name. Just like Daddy calls you sprout, but your name is Lily."
Alexis watches her sister consider Kate's words. After a few seconds, the girl shrugs.
"I fink it's Babe."
Alexis snickers, reaching over to wiggle her sister's knee. "Hey, Lil, what's my name?"
"And what's her name?" she asks, pointing to Kate. "You call her Mommy, but what's her other name?"
"Kate!" she yells in a credible imitation of her father. Beckett smothers a laugh in the baby's shoulder as Alexis purses her lips to hide her own amusement.
"That's right. And do you know what Gram's name is?"
Lily thinks for a moment, but answers with a quiet, "Martha."
Kate rubs her belly, touching soft lips to the girl's cheek. "That's right. What about Grandpa?"
They smile together.
"What's Daddy's name?" Alexis asks again, watching the man himself step from the office and lean against the bookshelf behind his wife.
"Babe," Lily answers without a second of hesitation, jumping when her father chuckles.
"You called?" he teases, stepping forward to lift Lily from Kate's lap. He makes a show of smacking a kiss to her cheek and flipping her upside down until her hair fans out and she cackles with glee.
Kate shakes her head. "Tell Lily your name, Castle. She's being silly tonight."
"Lily? Our Lily? Being silly?" he mock-gasps. "Never!"
The little girl squeals. "It's your naaame, Daddy. I know it is."
"You know it is?" he asks, tickling her belly. "Daddy has a lot of names, you know, and some of them are flattering."
Beckett shakes her head in Alexis's direction. "Daddy's name is Rick, Lily. Don't let him fool you."
"Mommy's right; that is my name. Babe is what she calls me because she loves me, though," Rick explains, offering his wife an affectionate look. "So it's just as good."
"Oh," Lily says, though she doesn't sound convinced.
Rick grins. "Say, what's the preschool's policy on students having pink hair?" he asks, swinging Lily upright. "Because we're going to find out."
Kate gets to her feet, rubbing Lily's back. "It'll wash out before next week. Hopefully."
"And if not, she'll be the school rebel. She takes after her mom like that."
Kate rolls her eyes, but Alexis grins, glad to see his good humor returning.
"Are you ready?" Alexis asks, gesturing for her father to hand Lily over when he nods. She rubs her sister's back, whispering a reminder that it's sister night into the girl's hair to keep her from getting upset.
"Ready," Rick says, tweaking Lily's foot. "I called and pushed the reservation back, just to make sure we wouldn't be running in late."
"Good thinking." Beckett smiles, stepping around him to kiss Lily's cheek, then Alexis's. "Be good for Alexis," she instructs, rubbing Lily's back. "And enjoy your movie."
Rick swoops in after his wife steps back, bear hugging both girls. Alexis finds herself leaning into him, relishing in the comfort of her father.
"Have fun," she murmurs. "And don't come home too early. It's sister night; no parents allowed."
They smile, sneaking a couple of last kisses from Lily's cheek before moving to get their coats.
Everyone laughs when Lily lifts her head, chirping, "Bye, Mommy! Bye, Babe!"
As her father shuts the door behind them, Alexis hears Kate concede, "Maybe I should use your name more often."
A/N: This ficlet was prompted an insanely long time ago by an Anon on tumblr as a response to this post: bunysliper tumblr slash post/128802076010/ cutielife-i-babysit-for-a-girl-who-use-to-think - Anon, if you're still out there, I hope you see this!
Thank you all for reading, I hope you liked it!