This is actually the canon/endgame-Peraltiago version of a drabble I wrote for a Peraltiago Advent Calendar I'm doing on AO3 (under the same pen name, if you want to check it out). I liked the idea and was kinda frustrated I couldn't do more about it since it's a fake-dating AU so I decided to redo it lol.

There's a lot of things Jake still didn't know and learns about the Santiago family while staying at their house for the Christmas holidays for the first time since he and Amy started dating. For instance, decorating a Christmas tree is a very important tradition for them – something that should not be messed with.

It's still early in the morning when a knock on the door suddenly wakes them up on their first morning at the house. A small enthusiastic voice – one of Amy's nephews – pleads them to go downstairs.

"We're putting up the Christmas tree!" Mason chants as if to encourage them to hurry up.

Amy's out of the bed in record-time and forces Jake to do the same despite his protesting grunts. She knows he's not a morning person.

When they finally emerge from Amy's old room and enter the living room, everyone is already gathered around the naked tree. It's surrounded with boxes full of neatly labeled and perfectly organized Christmas ornaments. The Santiagos have been waiting for them – without wasting another second, special assignments are given as soon as the couple arrives. They don't even have time to eat breakfast first.

Jake doesn't complain, but his stomach does.

He simply obliges as he takes a first bauble out of its designated box, then repeats the process several times. From time to time, he shoots some glances at the people around him and how focused they all seem to be, taking their task really seriously. Their thoroughness makes him smile amusedly. Soon though, he's stopped in his tracks by Amy – she appears out of nowhere.

He notices the judgmental and horrified look in her eyes when he turns to sneak a proud glance at her. The witty comment he was about to make gets stuck in his throat and his grin falters a little.

"What are you doing?" she asks.

"Putting up some baubles as requested." Jake shrugs as he places another one onto the tree to accompany his words.

Amy shakes her head. She takes down the bauble.

"You're not doing this right." She replaces it a few inches away from where it initially laid. She then takes a step back to watch her work. A new satisfied smile appears on her softened features.

"How can't I be?" Jake complains. He can't see what she did that's different – and supposedly better – than him.

"Look. You put two red baubles next to one another. It can't work." She points. It seems obvious to Amy but he still doesn't understand the big deal about having two ornaments the same color side by side.

She never complained, during the previous Christmases they spent together or even with their own tree they put up together at home, about the way he decorated them. He doesn't wait to tell her so.

"Well…" she trails off and averts her gaze. It makes Jake pause. "That's because I always redid it whenever you wouldn't watch." She shamefully admits as she puts her eyes back on his. She smiles apologetically.

Jake opens his mouth at the confession but not a word gets out – he's in shock.

"I'm sorry babe, you know I like things to be done thoroughly!" Amy tries to defend herself. It seems to work, because he ends up smiling at her – something fond and full of adoration.

"I know. I love you for that. And that's why I'm gonna let you finish for me, huh? I don't want your whole family to hate me because I messed up with the tree. Not when I'm finally getting along with your father."

He hands her a bauble. She lets out a chuckle and softly pecks his lips. Her eyes are shining with a new glow when she draws away. "I love you too."

Having nothing else to do, Jake goes sit on the couch next to the wife of one of Amy's brothers. She seems to have been banned from the whole process too.

"Don't take this personally." The woman laughs when she hears him sigh. "They're really serious about that whole 'dressing-up the Christmas tree' thing. If it can make you feel any better, Daniel and I have been married ten years and I'm still not allowed to touch the tree. Even my son reprimanded me one year." She points towards the same little boy that woke Amy and him up earlier.

He watches as Mason is concentrated in adding a tinsel starting at the top of the tree with his father's help.

Jake turns his gaze back on the woman with a smile. "Actually it does, thanks."

Despite what he told Amy, he still felt a little bad about being left out on something that seems so important for her and her family.

After that, both of them fall silent for a while. They watch as the others meticulously decorate the tree. Jake's gaze remains stuck on Amy – how focused she looks with a frown on her forehead and how her face seems to suddenly lit up every time she adds another ornament onto the tree. A dreamy grin quickly forms on his lips. She's absolutely adorable – a sight he certainly doesn't get tired of.

Good thing he's going to spend the rest of his life with her then, as the small ring on her left-hand finger shining against the Christmas lights she's now hanging proudly shows.

"So, excited about the wedding next year?" As if she was able to read his mind, a voice rising at his side takes him out of his contemplation and makes him start. When he looks back at Daniel's wife, he sees her staring at him. His beam grows even bigger and brighter at the mention of the event of 2018 for him and his fiancée.

"So excited," he sincerely – and excitedly indeed – says. "I can't wait to be Amy's husband. She's truly the most amazing person I've ever met."

The woman smiles at him knowingly. "Married life truly is the best." She shoots a quick glance at her own husband and their child – it's easy to read how much she cares for them inside her eyes.

Jake can only wish for a similar future for him and Amy as he does the same and turns his gaze towards her again. A future full of love and some 'mini-them,' celebrating together as a whole family.

They keep talking about the upcoming wedding and everything the couple still needs to work on until the woman's son suddenly approaches them. At first Jake thinks he's coming for his mother but, to most of his surprise, it quickly appears that it's not her he's actually seeking. He's got something in one of his hands and a sheepish look on his face as he watches the detective with big impressed eyes.

"Hi, buddy." Jake tries to ease the palpable tension. He's feeling just as uncomfortable as the little boy. Indeed, though he's made some progress during the past few years, he still doesn't know much about children or how to act around them.

The fact that everyone has stopped in what they were doing and now has their gazes stuck on the pair truly is of no help either.

Finally, without a word, the child takes another step and gives him what's in his hand: a big decorative star that's supposed to be the tree topper. Jake manages a smile through his confused frown as he thanks him then looks back at the boy's mother, full of questions. What is he supposed to do with this?! He has no clue but he can tell from the woman's grin and all the 'aww's rising around that it must be a big deal.

"It's a family tradition." Amy steps in to explain what's going on. She's fully beaming too. She puts a hand in her nephew's dark hair and gently ruffles it.

"We don't really know how far back it goes, but some great-great-grandparents came up with this idea so that there wouldn't be any fight over who gets to hang up the star at the top of the tree. They said the youngest of the family gets to do it. And well you're not the youngest but Mason did it last year already so since you're the newest addition to the family, he wants you to do it this year."

There's some hint of emotion in her voice and a blissful glint in her eyes. His soon fill up with tears he has to fight back. He's overwhelmed, his heart tightening in his chest at the sweet gesture and mention of him being part of this family. As he already told Victor at Thanksgiving, it's something he's always dreamed of. To be part of something.

(When he shoots the man a quick glance and is met with a knowing wink, he can't help but suspect the idea might actually be his. A single tear rolls down his cheek. He quickly wipes it off.)

"Oh well, thank you buddy," he says again and smiles sincerely as he lays his eyes back on the child. Mason only shyly smiles back at him before seeking comfort inside his mother's arms and hides there.

Jake then doesn't waste any more second – he stands up to put up the star.

"Wait." Amy stops him as he's about to place it on top of the tree. "You have to make a wish first. It's part of the tradition."

He only pauses for a second, his gaze stuck on her, piercing through her core. He doesn't have to think too long to come up with something to wish for. When he's done, he goes back next to his fiancée and the rest of her family. He wraps an arm around her waist and kisses her head as they all watch their final work.

As he looks at it with more attention, Jake has to admit the tree looks really beautiful, enlightened with fairy lights and decorated in matching red and white colors.

(Now he understands why putting two red baubles too close to one another wouldn't have worked.)

"What did you wish for?" Amy turns her gaze away from the tree after a short while to put it on Jake. She's wearing a curious, yet amused beam on her face.

He lets out a chuckle as he shakes his head. "Uh-uh. Can't tell. Otherwise it won't come true." He mysteriously tells her, teasing her. Amy tries to argue but for only answer, he kisses her pout away.

(It's only one year later that he tells her. He's sure that he came true now, as he watches her decorate their Christmas tree in her pajama pants and a slight bump starting to show off her top.

"I wished for a kid of our own," he says while he walks towards her to wrap his arms around her from behind and kiss her neck, softly skimming her belly with his thumbs.)