AN: Ok I shouldn't start a new fanfic, cause I have to update Cure my tragedy. But I've had this idea in mind all day and I had to write it down. Besides, it's a one shot, so after that I'll work to update my other fic.
It's a songfic based on Miley Cyrus's song Stay. I fell in love with this song the moment I heard it. It made me think about Addison and Derek. I'm not really satisfied with how I wrote it, it was better in my mind. But in my defense, I had a tough midterm today, so I'm excused. I hope you'll like it anyway.
One last thing: I never re-read what I write, cause if I do, I always feel the need to delete everything. So I'm apologizing for the mistakes you will find. And remember: even if I live in the US, English is not my first language.

It's set in season 1, Derek is in Seattle and he's with Meredith, when Richard told him that he's planning on calling Addison for the TTTS case. Derek realizes that he's gonna see his wife and starts thinking about her, so he decides to tell Meredith the entire story and calls Addison himself. Oh, Addison stayed with Mark for a little more than one month, but she didn't get pregnant.

DISCLAIMER: As usual I do not own anything. Grey's Anatomy belongs to Shondaland and Stay belongs to Miley Cyrus and unfortunately, Addison/Kate Walsh doesn't belong to me

Please review.

Stay

Well it's good to hear your voice
I hope you're doing fine
And if you ever wonder
I'm lonely here tonight
I'm lost here in this moment
And time keeps slipping by
And if I could have just one wish
I'd have you by my side

Ooh ooh, I miss you
Ooh ooh, I need you

It has been two months since Derek left New York. Two months since he found his wife naked in his bed with his best friend. Two months without a call, a text, two months without any contact.
Addison missed him. She missed him like crazy. She cried every night, even when she was with Mark. She couldn't help it.
She was lying in her bed alone, like every night in the past two weeks. She had tried to stay with Mark, because she wanted to believe that she hadn't thrown away her marriage for one-night stand, but it didn't work out. It wasn't just because Mark was cheating on her. She kinda expected him to do it. It was because she was still in love with Derek and she couldn't lie to herself and to Mark, who was still her best friend.
She had lost track of time. How long it has been since she got home that night? Two hours? Maybe three? Time was slipping by while she was thinking about his husband. She wondered where he was, what he was doing. She missed him so much.
If she could turn back time, she wouldn't sleep with Mark. Yes, she was lonely and upset with her absent husband, but sleeping with Mark has been her biggest mistake. Maybe if she had talked to Derek, they would have figured everything out, but instead she decided to cheat on him, just because of her need to feel wanted.
She sighed. If she had just one wish, she would ask to bring Derek back to her. She needed her husband by her side.
The phone ringing brought her back to reality. It was late, almost 1 am. She hoped it wasn't the hospital calling her, because she wasn't in the mood to spend the night in surgery.
She grabbed her phone and checked the caller ID. Her heart skipped a beat when she saw the name appearing on the display.
"Derek?" she answered softly.
"Addison." said Derek on the other side of the phone and Addison started crying softly.
"Oh my god, Derek. I'm so happy to hear your voice. Where are you?" asked Addison sobbing. "I'm sorry, Derek, I'm so sorry."
"Addison, I don't want to talk about it on the phone." replied Derek a bit harshly. "I'm in Seattle, I'm working for Richard Webber at Seattle Grace Hospital. He wanted to call you cause he needs your help on a TTTS case, but I thought it was better if I called you myself. Would you come to Seattle as soon as possible?"
Addison sighed. "So it's just for work?"
"No, I think it's time for us to talk. I'm sorry I left without even giving you the chance to explain yourself." said Derek. It wasn't planned for him to apologize, but the disappointment in his wife's voice made him say those words. It was true, anyway. Yes, finding Addison in bed with Mark had been a shock for him and he was still mad, but he should had given Addison the chance to explain. Addison wasn't a cheater, she wasn't the kind of woman who did something like this just for sex. There was a reason why Addison did that.
"You don't have to apologize, Derek. I understand. I'll be in Seattle tomorrow morning." said Addison, opening her laptop to book the first available flight to Seattle. "Derek…it's really good to hear your voice. I hope you're doing fine."

Well I try to live without you
But tears fall from my eyes
I'm alone and I feel empty
God, I'm torn apart inside
I look up at the stars
Hoping you're doing the same
And somehow I feel closer
And I can hear you say

Ooh ooh, I miss you
Ooh ooh, I need you

Addison was on the flight to Seattle, thinking about her conversation with Derek. She was so happy she was going to see him in a few hours, but also terribly worried. She wanted him back, she wanted her husband back. She wanted the Derek she fell in love with, the one who went to bed with her every night, who used to take her out for dinner at least once a week, who waited for her on top of the Empire State Building while she was watching the whole city through the viewfinder for the hundredth time, cause he knew she loved it.
She had tried to move on, she really did. She had tried to find a way to live without him, but she failed. There was no life for her without Derek. A tear escaped from her eyes. For the whole time he was gone she had felt so alone and empty, so torn inside. Every night she had looked up at the stars, hoping that, wherever he was, Derek was doing the same. It had become a sort of ritual for her, it was the only way she had to somehow feel closer to her husband. And now she was going to see him.
She replayed in her mind the words he said to her, his voice so cold at first, but in the end of the conversation she heard him whisper "I miss you". So he had missed her. Maybe there was still a chance for them. Maybe their marriage wasn't over yet. She was determined to fight for him, fight to have him back and to make him forgive her. She wasn't ready to let go.

I love you more
Than I did before
And then today I don't see your face
Nothing's changed
No one could take your place
It gets harder every day
Say you love me more than you did before
And I'm sorry it's this way
But I'm coming home, I'll be coming home
And if you ask me I will stay

She arrived at Seattle Grace and took a cab to the address Derek gave to her. It was late, she hadn't been able to find a flight in the morning, and Derek had invited her to come to his place for dinner. She felt a sense of anticipation growing inside her. It was like coming home after a long time. Even if she hated Seattle and its rain, she was happy.
When the taxi stopped, for a moment she thought Derek had given her the wrong address. She was in the middle of nowhere and the only thing there was a trailer. But then Derek opened the door, and Addison's heart seemed to explode. His hair was different, but he was still her Derek. Addison felt like she loved him even more than before. All those time apart just made her realize that no one could take his place, there was nothing she could do about it. She just hoped that Derek felt the same about her.
He was still on the door, not moving, when she got closer to him, not really sure about what to do and how to greet him.
"Derek…hi!" she whispered, trying to control her tears.
Derek smiled softly, moving closer to her and finally wrapping her in a hug. Addison let herself get lost in her husband's arms. God she had missed him so much. "I'm sorry, Derek." she sobbed, her head buried in his chest.
"It's ok, Addison. Come on in." said taking her luggage and guiding her inside. "I've cooked some pasta. I thought that we could eat and then talk a little."
Addison nodded and sat on the table. They ate in silence, they tried some small talk but it was still too awkward.
After they finished dinner, they sat on the couch, none of them really knew where to start and what to say.
"So…"started Derek unsure. It wasn't really his place to start that conversation, he wasn't the one who had to do some explaining, but he was the one who asked Addison to come, so he felt like he had to say something.
"Derek, I'm so sorry." repeated Addison. "I screwed up and trust me, if I could, I would take it back."
"Addison, stop saying that you're sorry." Derek interrupted her. "I know you are. Now I wanna know why. Why you did it? Why Mark?"
"You weren't there, Derek." whispered Addison, the tears streaming down her face. "You were always at the hospital, you weren't coming home anymore. You sent Mark over all the time, every birthday, every anniversary… I even spent New Year's Eve with him cause you were on call. I felt lonely and Mark…Mark made me feel like I was worth it, like I was wanted. I know what I did was wrong, I should have talked to you instead of falling into Mark's arms, but I was desperate, Derek. That night you found us, it was the first time…I was a little drunk and I started crying cause I was missing you and Mark was comforting me. The next thing I know is that we were kissing. I wanted to stop, Derek, I really did, but I couldn't, cause you weren't there and I needed to feel something. And I have to be honest with you, Der…after you left I stayed with Mark. I thought I was in love with him, cause he has been there for so long while you weren't, but I realized that I was just fooling myself, that I was just convincing myself to love him, cause I didn't want to accept that I had ruined our marriage, my life, for a fling. And after a little more than one month, I left him. Not only because he was cheating on me, he's Mark, he's a manwhore, he doesn't know what it means to be faithful…but because I knew it couldn't work…I was still in love with you, Derek. I am still in love with you and I'm sorry. If you decide to give me another chance, I swear to you I won't screw up ever again. Can you forgive me, Derek?"
Derek didn't speak for a while, trying to process Addison's words. Suddenly he realized that his wife wasn't the only one to blame there. It was true, he had been absent for a very long time. He had spent the last three years of their marriage working, not caring about Addison. He had sent Mark over to keep her company, so she wouldn't feel alone. He practically pushed her in Mark's arms.
"I'm sorry, Addison." he started and Addison, thinking that he was apologizing for not being able to forgive her, cried harder. "I'm sorry I was absent. I'm sorry I started to put my job before you. I'm realizing just now how wrong I was and if I look at the situation under this light, I can't blame you for doing what you did. Sure, you could have talked to me, but what I'm trying to say here is…it's not entirely your fault. And I understand why you decided to stay with Mark. Thank you, for being honest with me. But now I have to be honest with you. I found a girlfriend here."
"What?" gasped Addison, knowing she had no right to be upset about it, but still feeling hurt. Derek had a girlfriend? Her Derek, seeing someone else, maybe even being in love with someone else.
"We met the first night I was here, in a bar." explained the neurosurgeon. "We were drunk and we slept together. Then we found out that we were working together and we started going out together. I thought I was falling in love with her. She kinda is the Anti-Addison, but in so many things she reminds me of you when we were interns. She's strong headed, but also kind and sweet and she would do anything for a patient. It was like I was drowning and she was the fresh air. I really thought I could move on with her. But when Richard told me he wanted to call you, I started thinking about you. I realized that I couldn't be in love with Meredith, that's her name, cause I still had feelings for you. What you did and all the anger weren't enough. I left without saying a word and I hoped that moving to another city was enough to forget, to start fresh. But it wasn't, because there was no closure between us. That's why I called you, that's why I asked you to come here. I needed a closure."
"So that's it? It's over?" cried Addison.

I never want to lose you
And if I had to, I would choose you
So stay
Please always stay
You're the one that I hold on to
Cause my heart would stop without you

The trailer was silent. Derek hadn't answered the question and none of them dared to speak. The only sound was Addison's sobbing. She really was convinced it was over.
"You know…" said Derek after a while. "Mark and I had always liked the same girls. In high school we always wanted the same girls. And of course all of them fell for Mark, cause he was a football player and he was charming and knew what to do and say to make them fall for him. I was just his geeky friend. It has always been like that. When we started Med School and we met you, Naomi and Sam, I fell for you since the beginning. And of course Mark fell for you too. When he told me, I thought I couldn't stand a chance against him, I was sure you would have chosen him over me. So when Sam told me that he had asked you out but you had said no cause you liked me, I was the happiest man alive. When we started to go out together, when you agreed to marry me…god Addison, you have no idea how happy you made me. And when I came home that night and I found you in our bed with Mark…everything came back on me. All those years in high school and in college…all those girls…and you…you were mine, Addison, you were mine…and you slept with him. I knew he was in love with you, he had always been in love with you. We both were. But you were mine. That's why it hurt so much. Because I was sure you had chosen me, but apparently I was wrong."
"Derek, you weren't wrong!" exclaimed Addison, taking Derek's hands in hers. "I chose you. I would always choose you. I'm still yours, Derek. If you want me, I'm still yours. I told you, Mark was a mistake. You're the one that I hold on to. I can't live without you, Derek!"
Derek remained in silence again. Then he finally said "I ended things with Meredith. I told her about you, I told her that I'm married, that I left you cause I was mad. And I told her I'm not ready to let you go."

I love you more
Than I did before
And then today I don't see your face
Nothing's changed
No one could take your place
It gets harder every day
Say you love me more than you did before
And I'm sorry that it's this way
But I'm coming home, I'll be coming home
And if you ask me I will stay
I will stay
I'll always stay

Addison's eyes widened. "Really?"
Derek smiled and nodded.
"Derek, I love you so much. I never stopped loving you. Do you want to give us another chance?" asked the redhead, her voice and her eyes filled with hope.
"Addison, I never stopped loving you either." said Derek. "And when I saw you coming out from the taxi I knew I had to give you another chance. I missed you so much and I feel like I love you more than I did before. So, to answer the question you asked me before, yes, I forgive you."
Addison smiled happy and threw her arms around her husband, hugging him tightly. "Thank you!"
After a while they parted. "Well, it's late and tomorrow I have to see Richard pretty early. I better go to the hotel." said Addison standing up and grabbing her coat.
"Addison." Derek stopped her, grabbing her wrist. "I like it here in Seattle. I'm not sure I want to go back to New York. But maybe you can talk to Richard…he can give you a job…and maybe you can stay…"
Addison raised her eyebrow. "In Seattle? Or here, tonight?"
"Both." said Derek and he pulled her against him, kissing her deeply. It was sweet, but also passionate. It felt like they hadn't kissed each other since forever, but at the same time, that nothing had changed between them.
"So, what do you say?" asked Derek when their lips parted to allow them to grab some air.
"Yes, Derek." answered Addison. "I will stay."

And I love you more than I did before
And I'm sorry that it's this way
But I'm coming home, I'll be coming home
And if you ask, I will stay
I will stay
I will stay