I know you've waited a long time for Addison and she's finally here.

I apologize for the delay in updating, but life has been very busy.

Derek and Addison stare at each other for what seems like na eternity, until Nancy decides to break the eerie silence. So she takes a step forward and hugs her ex-sister-in-law while saying:

"I'm sorry, Addie."

"It's okay, I'm fine."

Addison states deepening the hug as she burns Derek with her eyes.

Derek almost smiles, nothing is more Addison than telling her she's fine when she clearly isn't, though it's good to know she hasn't changed. Soon Nancy walks away and asks:

"We come?"

"Clear."

Addison says still stoic and moves away from the door giving space for the brothers to enter the room. Derek swallows, hardly anything has changed in the room in three years, only the couple photos have been replaced by photos of a chubby, smiling baby, it's weird and bittersweet.

He soon recovers and asks in na arrogant tone:

"So where is my son?"

"Good morning to you too, Derek Shepherd."

Addison speaks and the ironic tone is very similar to the one she used on her arrival in Seattle. Surprising him, he looks at her in bewilderment for a few moments, but then the sound of laughter distracts him.

Derek identifies the sound coming from the kitchen and practically runs into the room. There he sees a man sitting on his back and behind him Archer holding a smiling little boy. As soon as he recognizes Derek's presence, Archer pulls the boy closer to his chest and says wryly:

"Derek Shepherd, did you finally decide to show up?"

"I would have shown up sooner if your sister hadn't been..."

"I think you better think before you finish that sentence."

The other man speaks, standing up and coming face to face with Derek, then gives a crooked smile and extends his hand:

"Peter Wilder."

Derek extends his hand and asks:

"So you're the boyfriend?"

"And you're Derek. It feels good to put a face to a name."

Derek nods uncomfortably and then turns to Archer and the little one who looks so comfortable in his arms. Derek approaches, holding out his hands and Archer asks in a petulant tone:

"Who said I'm going to let you hold my nephew?"

"Archie!"

Addison's voice echoes from the kitchen door and she stares at her brother raising her eyebrows, Archer gives a dejected sigh and hands the child over to Derek.

Time seems to freeze at that moment, Derek holds his son who looks at him with big and sweet eyes. He waits for the boy's reaction, cries, refuses, but what comes is a soft touch to his hair and then a bright smile. Derek smiles back as tears form in his eyes and he says:

"Hi Chris. I'm your dad, I'm Derek."

"Deek."

The boy pronounces it strangely and nods. Derek smiles even wider and then carries him into the living room, needing to spend a few moments alone with the boy. Fortunately none of the others follow.

With Chris in his arms, Derek walks across the room. He shows the boy the pictures, whispers funny things in his ear and strokes his back trying to make him as comfortable as possible. And Chris really looks comfortable, with his little arms around his dad's neck, so he points towards the huge Christmas tree and says:

"Citiman"

Derek smiles and nods kissing his son's temple.

Soon he hears footsteps and the four enter the room at the same time. Addison crosses her arms and takes her time to watch Derek with his son, then turns to Archer and asks:

"Can you accompany Nancy and Chris on a walk?"

"Clear."

Archer states with feigned enthusiasm, but goes to get his car keys, giving Derek na odd look. Nancy goes upstairs to put more clothes on Chris, while Pete pulls Addison in for a soft kiss before speaking:

"I'll go home, make room for you to talk. I'll be back before dinner."

"Thanks."

Addison smiles and pats his chest before escorting him to the door. Derek just watches the moment awkwardly. A few minutes later Nancy comes downstairs with Chris fully dressed for the cold, Addison kisses her son's forehead and opens the door for them to leave.

Alone in the room, Addison and Derek face each other in another horrible silence, she approaches just as Derek asks:

"How did you dare to do this to me?!"

Her tone is completely accusatory and Addison sighs deeply before replying:

"It's not like I planned it, Derek."

"That doesn't change anything."

Derek speaks in na even more aggressive tone and Addison runs her hands through her hair in frustration before asking annoyed:

"Are you going to let me explain or not?!"

"It starts by explaining how you had the courage to leave without even talking to me?!"

Addison frowns and lets out a wry half smile as she asks:

"You really have the guts to ask me that?!"

"Yes! You just left, Addison, without saying anything. You ran away from me."

"Because I needed to get away. I needed to get out of that horrible trailer, this horrible city and our failed marriage!"

Addison almost screams, but then she runs her hands over her face and takes a deep breath, then speaks in a calmer tone:

"I just needed to get out of Seattle and start my life over."

"And the pregnancy?"

"I didn't find out until two weeks after the divorce."

"And you didn't think to call me."

Derek states angrily, but Addison gives a wry smile as her eyes fill with tears, she drops her face and speaks softly:

"I called... I called the next day."

"Didn't call."

"I called, but Meredith picked up. Two weeks after our divorce there was another woman on her phone."

Addison says in a hurt tone and Derek lets out a deep breath as he tries to apologize:

"Addie..."

"It's okay. It's not like I didn't know you loved her, I just... I just didn't want to mess up her life. I decided I'd have time to tell her when I was ready."

"But then her pregnancy got difficult?"

Derek asks half already knowing the answer and Addison nods silently before sitting down and starting to speak:

"After calling you I decided to give myself some time, but I looked for Nancy because I wanted her to take care of me. At first everything went well, but then I had a kidney infection and then another... until the Hydronephrosis started. ."

"Addie..."

"At that moment I looked for her mother and the other girls and told her, because I needed support. Amy moved in with me, her mother was always there, Archer was too. I spent half the pregnancy being hospitalized, but at 30 weeks, acute kidney failure and I went into a coma."

Addison stops talking with a deep breath and Derek feels his eyes water. Soon she recovers and speaks again:

"They did na emergency C-section and took Chris to the NICU. Luckily he wasn't that weak and by the time I woke up and was aware enough of everything he was out of danger."

"I'm sorry about all this, Addie."

"Me too..."

"But why didn't anyone call me when this happened?"

"Archer and his mother thought it was a betrayal of me."

"And then?"

"It took me a while to recover, first physically, then emotionally. I had postpartum depression. I couldn't face you before and the more time passed, the harder it got."

Addison confesses and a tear finally flows. Derek immediately walks over and holds out his hand wiping away the tear as he speaks:

"It's okay, Addie."

"No, it's not. I deprived you and Christopher of each other's company and there hasn't been a day that I haven't condemned myself for it."

"Weren't you ever going to tell me?"

Derek asks with more curiosity than judgment and Addison explains:

"Of course I would! I just didn't know how. When your mom called me saying you were coming for Christmas, I knew you'd find out eventually. I was getting ready for this and now... You're here... "

Addison speaks before letting out a deep sigh which makes Derek caress her cheek as he speaks:

"I'm here. I was angry the moment I found out, but now I'm not. I can't imagine what you went through, Addie."

"Don't you hate me even more for that?"

"I don't hate you for anything. I can only thank you both for getting along. And I just want to think about what we're going to do from now on."

Derek speaks with a slight smile which Addison returns before asking:

"And what are we going to do?"

"I want to spend time with my son until New Years. And I want to register him. By the way, what's his full name?"

"Christopher Ainsley Montgomery."

"I never imagined my father's name would be mixed with Archer's."

Derek speaks with humor and Addison can't help but laugh. For a minute they are lost in each other's eyes, but then Addison recovers and asks in a cracking voice:

"You're not going to take him away from me are you?"

"Of course not! Never!

I still don't know how we're going to organize things, living on one side of the country, but we're going to work it out."

Derek says it with complete conviction and Addison lets out a sigh of relief before asking:

"Do you want some wine? Because I definitely need one."

Derek nods smiling and then she leaves the room. Soon Addison comes back with a bottle and two glasses, they sit facing each other and after the first sip they ask at the same time:

"What about Meredith?

"What about Peter?"

Both laugh a little embarrassed. After a moment Derek speaks again:

"Meredith is fine and she'll understand. She's not twelve anymore."

Derek talks smiling and trying to be fun. Addison laughs, but he's not sure she bought it. The truth is, he has no idea how Meredith is going to react or if her reaction is going to matter. Chris is the most important thing right now. Addison nods, still smiling and replies:

"Pete is fine too. We've only been together for a few months and he always knew Chris had a father. It's not like he expected to replace anyone."

Derek nods and asks:

"Is he friends with Sam and Nae?"

"Yes. They worked together in LA, but Pete's wife died a while ago and he felt like he needed a fresh start. We met when Nae came to a convention and we became friends first."

"He seems like a nice guy."

"He is."

Addison speaks with a sincere smile and Derek can't help the pang in his stomach. He speaks without thinking:

"I wonder how things would have turned out if you hadn't left."

"Derek..."

"I wonder how we would have found out about the pregnancy together. What it would have been like to go through all this with you and the happiness of seeing you two get out safe and sound."

Derek states before letting out a deep breath and Addison finds herself standing up, she kneels down facing him and holds his hand as she states:

"It wasn't your fault. I decided to leave because it was the best thing to do at the time."

"Because I was horrible to you."

"It was. You were horrible to me in Seattle and you were horrible to me here in the first place, but you stopped loving me and that's not your fault."

"Addie..."

"Derek, it's okay. Chris and I are great, you have someone who makes you happy, so do I. We don't need to grieve and apologize anymore."

Addison states and holds his hand, Derek leans forward and they look deeply into each other's eyes. Suddenly their lips are very close and neither of them can pull back anymore.

The kiss, like na explosion of conflicting feelings, is raw and intense. Soon Derek sinks his fingers into Addison's hair as she bites her bottom lip, deepening the kiss even more. They only stop when Nancy's voice echoes through the front door:

"What the hell does that mean?!"

Addison jumps, nearly landing in the middle of the room, while Derek immediately gets up off the couch. They're about to give explanations, but the mother half-falling to the floor causes Chris to start a deep, hearty laugh. The three adults start laughing along with the boy and Derek can't hold back a tear at the sound of his son's laughter as his little blue eyes sparkle and his little teeth are showing. Derek then takes his son from his sister's lap and is surprised when he speaks softly:

"Rek..."

It's Addison's turn to approach, she smiles at her son and caresses his cheek as he says:

"Chris, Derek is your daddy. I know he was far away, but now he's here and I'm sure he's going to be the best dad in the world."

Obviously Chris doesn't understand the weight of the words, but Addison and Derek exchange emotional glances. The little boy then leans his arms towards his mother and Derek hands him over. Addison prefers to walk away from her ex-husband and turns to Nancy again in embarrassment:

"Did something happen for you to come back so soon?"

"Chris wanted the fop and Archer wanted to find someone."

Nancy says the last part rolling her eyes and Addison follows suit, but then smiles explaining:

"Fop is the giant bear that Archie brought him yesterday. I'll go get him and change his diaper, feel free."

The redhead then leaves the room with her son in her arms. Nancy casts a sly look towards her brother as she asks:

"What was it that I witnessed here?"

"Na error in judgment. We let old habits take over."

Nancy rolls her eyes unconvinced and teases:

"Are you sure that was all?"

"Of course! I love Meredith."

"I didn't say I didn't."

Nancy teases once more and Derek huffs before snapping back:

"Enough, Nancy pants."

Nancy frowns at the old nickname and decides not to continue the little argument.

It doesn't take long for Addison to come back into the room with Chris in one arm and a bear bigger than he is in the other, Derek immediately helps her by picking up her son and she invites:

"Shall we order something for lunch? While we wait I feed Chris."

Nancy and Derek agree. Addison takes her son into the kitchen, followed by Derek, while Nancy stays in the living room taking orders.

Derek watches, Addison feeds Chris and can't help but think of how many times she's imagined this scene, the wife sitting in her kitchen feeding a tiny human being who is the perfect blend of them. When finishing Addison notices Derek's distant gaze and asks:

"It's all right?"

"Uhm... It's just that I've imagined it many times."

Derek speaks with a soft smile which Addison returns with a little blush before picking Chris up in his arms and carrying him to be cleaned. She comes back in a few minutes with the little boy chuckling and extending his arms towards Derek who catches him immediately.

Soon Nancy returns to the kitchen with lunch and the three of them sit down to eat. Lunch is silent and even a little awkward, with Addison and Derek avoiding each other's gazes while Nancy watches them intently.

When the three finish eating, Chris is already asleep, so Nancy takes the cue:

"Let's go, Derek?"

"It's early."

"It's not. Look, I know you want to spend as much time with Chris as possible, but we need to get back to Connecticut."

"But I'll come back here with you guys tomorrow."

"It's all right."

"I'll be back tomorrow, Addison."

"Chris will be waiting for you."

Addison speaks in a soft tone. Derek nods and kisses his sleeping son's forehead before leaving the house.

Addison lets out a deep sigh as soon as she hears the door close, she takes her son into the bedroom, tucks him into his crib and grabs the baby monitor before heading to her own room and curling up under the covers.

It's early evening when Pete enters Addison's room, she's lying on the bed playing with Chris and flashes a smile that doesn't reach her eyes when she sees her boyfriend. After some time, Chris falls asleep and Addison sits next to Pete on the couch, she lets out a deep sigh and confesses avoiding his gaze:

"Me and Derek kissed."

Pete is silent just looking at her who continues:

"I know you must be thinking I'm a horrible person, but I swear it was by accident... It was a moment and..."

She stops talking with tears already forming in her eyes, Pete pulls her chin gently making her look at him and says:

"It's okay, Addie."

"OK?"

"You haven't seen each other in two years, emotions were running high... It's okay."

"Aren't you going to leave?"

"You want me to go?"

Pete asks arching his eyebrows, Addison smiles caressing his face and says:

"No. Definitely not."

"Fine. Because I wouldn't go anyway."

They laugh together and Pete pulls her closer, he looks into her eyes and thanks:

"Thanks for telling me."

Addison just smiles nodding and Pete kisses her forehead before snuggling her into his arms. She closes her eyes, feeling the comfort of her boyfriend's arms, but all she can think about is spending half the day with Derek.

Derek throws himself on the bed exhausted and hangs up the phone to avoid talking to Meredith.

He still doesn't believe he's met his son, doesn't even believe he has a son, but Chris is there, he's real, and he's the perfect mix between him and Addison. Thinking about his ex-wife and all she's had to go through alone makes his stomach sink. It's inevitable not to blame yourself for not being by her side, for not holding her hand in difficult times, for not being there for Chris when he was born so fragile. Guilt gnaws at him, but Addison's words of absolution echo in his mind, his Addie, always selfless even when people don't deserve it. He smiles thinking about how amazing she looks with her son, just like he always imagined she would.

Derek curls up to sleep and the last thought that pops into his mind is that he's kissing Addison, the confused, desperate kiss that Nancy interrupted.

That's it.

I hope you liked it and that the next one doesn't take so long.