A/N: Beta by Trish. She makes all my words pretty.

Disclaimer: not mine.


Richard Castle just has to be up to something. Kate has known her husband long enough to realize when he's being sneaky and her husband is definitely up to no good. He's been spending lots of time with Max, talking to him in hushed tones. And Kate has no doubt in her mind what he's trying to do. He's trying teach their son new words.

Kate's not entirely convinced that Castle's above petty revenge. Max's first word was "Mama", much to his dismay, and since then their son's vocabulary has been steadily growing. Just last month she caught him trying to teach Max the word "boobies". Their son is now able to say quite a few of the more basic words but attempts with larger words have been mostly unsuccessful - albeit with some hilarious results including Alexis' attempt to teach him the word "denouement" which deteriorated into "Doo Doo Man". Kate might have overheard Max saying "bane" the other day as Castle bathed their son, but that doesn't make much sense. Either way, she is content to let things play out on its own.

"Max, come say bye to Mommy," Kate calls out as she leaves the kitchen area, her coffee-to-go cup in hand. A pattering of uneven footsteps alerts Kate to their son's escape from his father. Max can walk steadily by himself but nowadays their son is learning how to run in short bursts. Keeping up with their little ball of energy is about to get just a little bit harder.

Kate picks Max up easily after he collides head on with her leg, smattering kisses all over his little face and earning giggles in return. Hearing Castle approach she directs her attention back to her son. "Max, you be good for Daddy, okay? Mommy's going to work now but I'll see you two at lunch. Can you give me a kiss and say bye mommy?"

Max presses a slobbering kiss to her cheek with a loud "Love mommy, bye bye!" before Kate puts him back on the ground. Returning to work has been hard and Max's separation anxiety is still touch and go at this point. Kate is relieved he isn't throwing a tantrum this morning.

"And you," Kate says, resting a hand on Castle's chest, "be a good daddy. Our son isn't a Pavlovian experiment for you to play with."

Castle winds a scarf around Kate's neck and tugs her closer. It was still early in October but the temperatures had begun falling rapidly the past few days. "I have no idea what you're talking about, Beckett," he says, pressing a kiss to her lips.

"Don't think I haven't seen you bribing our son with candy as you try to teach him new words. Max isn't a pet for you to train with treats." She smirks, heading for the door.

"How did you even-"

Kate narrows her eyes at him. She knew her husband had been stooping to bribes. "Castle, I'm a detective. I detect."

Castle pouts, picking up their son as she opens the door. Max's little legs begin kicking immediately as he tries to break free and make a run for the elevator.

"We'll see you at lunch."


Castle couldn't resist sending Beckett a text a few hours later.

I have a great idea for Max's Halloween costume.

His… positive reinforcement finally paid off shortly after Beckett left for work earlier this morning. Castle should probably consult with Beckett before buying Max's Halloween costume but surely his wife wouldn't be able to resist after she sees the product of his efforts from the past week or so. Castle clicks the "purchase" button without a second thought.

A few minutes later, his phone chimes with Beckett's reply.

Let me guess. Jedi knight or space cowboy?

Castle smirks and fires back a quick reply as he picks up their order at Remy's with Max in tow. Their son was already earning adoring looks from the regular staff.

Even better. Just picked up lunch for you and the boys. Heading over to 12th now.

The costume is supposed to arrive in three days but with a little help from Beckett's make up collection, Castle doesn't see why he can't give his wife a little preview.

He just can't wait to see Beckett's face.


"Bwains! Bwains! Bwains!"

Beckett's head whips up at the sound of her son's voice. She can't see Max – he is still short enough to be hidden from view by the desks – but Castle is never far behind their son and sure enough, she sees him walking up with two large paper bags containing their lunch.

Ryan and Esposito are quick to head over and exchange fist bumps and greetings with Castle.

"Max, what happened- Castle, did he fall or something?" Beckett is quick to pick up their son when she sees him covered in blood and a few stitches, with Max content to let his mother fuss over him. She quickly realizes it is merely make up.

"No, he's perfectly fine. Just, hold on- Max, what did you want to say to mommy?"

"Bwains! Give bwains!"

"What?" Beckett asks in confusion as Castle hands her a pack of gummy treats. Max stretches out his little hands and makes grabbing motions towards the candy.

"Bwain, mommy. Pwease?"

Beckett looks at the pack of candy again. They are brain-shaped gummy treats.

Castle beams proudly at his wife. "Our son is going to be the cutest little zombie for Halloween."


A/N: Hope you guys loved this as much as I did!