A/N This came into my mind after watching Private Practice last night. The ending is very AU.

All She Ever Wanted

Amelia Shepherd knew that something was off, but she wasn't sure what it was. The Shepherd house was crazy right now with her sisters and their boyfriends and fiancées and her brother and his girlfriend all there for Christmas dinner. Amelia really was not sure what Addison and Derek were doing, but she did know that Mark, her surrogate brother definitely had a thing for Addison. She was almost sure that Addison was trying to decide between two men and Amelia Shepherd hoped that Addison would make the right decision for herself. Amelia knew that her mother was not fond of the tall redhead, but Amelia also knew that her mother would fake it if Derek was happy with her.

Come to think of it, Amelia couldn't find Addison or Mark anywhere. She wasn't sure how long it had been since she had seen either of them and she really hoped that she was just losing them in the crowd. Of course it was hard to lose a tall redhead and a guy who she had known since she was born. Amelia saw her brother talking to Nancy's fiancée so Amelia knew that Addison was not with Derek. She felt a sinking sensation in her stomach as she made her way to the stairs. She wasn't sure what she would find Addison and Mark in the middle of but she wasn't sure she wanted to know.

She reached the top of the stairs and she started opening doors. First her sister's bedrooms and then her bedroom. She was relieved to find out that they were not in her bed. Finally she reached the end of the hallway. There was no way she was going to go into her mom's bedroom. Amelia respected her mother's privacy and she hoped that Mark and Addison respected Carolyn Shepherd's privacy as well. So the last bedroom to look in was the boys bedroom. Mark and Derek had grown up like brothers and they had shared a bedroom whenever Mark spent the night which was more often than not.

Usually Amelia would knock but this time she didn't see the importance. It would remove the element of surprise for her surrogate brother and Addison. Instead she put her hand on the knob and turned it and opened the door.

"Jesus Amelia!" Came the voice of her surrogate brother as he tried to cover himself up. He had been on top of Addison and in his haste to cover himself up he had rolled off of Addison, exposing her naked body to Amelia.

"Don't you ever knock?" Addison demanded. Her face was beet red and she could not believe that Derek's baby sister had caught her in bed with Mark. She was supposed to be with Derek and here she was lying naked in a bed with Mark, Derek's best friend and brother. She was grabbing at the leftover sheets to cover her body up. Amelia looked at the two of them, hardly disguising her disbelief.

"Aren't you supposed to be my brother's girlfriend? And aren't you supposed to be his best friend and brother?" Amelia demanded as she looked at both of them. Amelia Shepherd definitely had a temper and it was a well known fact that her mother had the same temper. She was also fiercely protective of her siblings despite being the youngest of the Shepherd clan.

"Get out Amelia." Mark ordered her. He wanted to save Addison from the embarrassment that he knew she was feeling.

"This is my mother's house." Amelia shot back.

"Mark, you should go." Addison told him softly. She knew that the Shepherds would never forgive Mark if they found out what he had done. Addison would feel a lot of guilt because this was his surrogate family long before she ever met them.

"I grew up in this house. This is my bedroom. Amy can't chase me out." Mark argued.

"It's Amelia Mark. You know fully well that only Derek gets to call me Amy." Amelia snapped. Mark looked at Addison who gave a slight nod. She still thought it was best that he leave the bedroom.

"Fine. Get out of the room while I get dressed." Mark growled. Amelia very quickly left the bedroom and waited outside of the bedroom. She still could hardly believe what she had walked in on. She wished she knew what Addison was thinking though Amelia had a feeling that Addison didn't even know what she was thinking. Inside the room, Mark was pulling his clothes on and desperately hoping that Derek wouldn't find out. Derek was his best friend and betraying him like this was never in the cards. Mark and Addison had just found themselves attracted to each other and as many times as they tried to stop what they were doing, they couldn't. He kissed Addison quickly on the lips before he left the bedroom. After he closed the door to the bedroom, Amelia grabbed his arm.

"What the fuck do you think you are you doing?" Amelia demanded of her older surrogate brother.

"None of your business." Mark snapped.

"When it involves my brother's girlfriend and my surrogate brother yes it is my business." Amelia insisted hotly.

"It just happened. We didn't plan for it Amelia." Mark told her patiently. He started to walk away from Amelia but he stopped dead in his tracks when Amelia spoke again.

"Do you love her?"

"More than anything else in the world." Mark whispered without turning back to face Amelia. He had always had feelings for her but for the longest time he had refrained from acting on them because of Derek. Derek was his best friend and as close to a brother as Mark would ever have. When Addison told him that she was confused and that she had feelings for two guys, that was when Mark had stopped thinking about what anyone else thought. All he cared about was what Addison thought. And in that moment was when they shared their first kiss.

Amelia watched Mark walk back down the stairs to rejoin the party and her instinct was to join him just so there was no suspicion about where he had been, but Amelia wanted to talk to Addison first. She needed to know that Addison wasn't fucking with Mark's heart and that there was actual feelings involved for Addison. Amelia could not believe that Mark was actually in love with his best friend's girl. She had never known Mark to fall in love and she had known him all of her life. She pushed open the door and she saw Addison's body hunched over and she was shaking. Amelia was almost certain that she was crying.

"Addie?" Amelia whispered as she closed the door behind her.

"I'm sorry you had to see that." Addison whispered before she looked up at Amelia. Addison's face was blotchy and Amelia was convinced that it was because of the tears that Addison was likely working on holding back.

"What's going on?" Amelia asked as she sat down on the edge of Mark's childhood bed.

"I love Derek, I really truly do, but when I'm with Mark…He makes me feel like I am the only woman in the world. He treats me like a Queen and I feel sexy and desired when I'm with him. I feel safe and comfortable when I'm with Derek. Safe and comfortable are good things but you can't build a life on feeling safe or comfortable." Addison whispered. She hated admitting these things to Derek's baby sister but she needed someone to talk to. Nancy had said more than once that Mark was good for only one thing and Kathleen always had her younger brother's back and Derek's other younger sister Jenna had never liked Addison.

"You don't want a life with Derek, do you?" Amelia whispered. Addison bit down hard on her lip and shook her head. She knew it sounded horrible, but she wanted what Mark could offer her.

"You want one with my surrogate brother." Amelia commented softly. Amelia knew that this was going to devastate Derek but she also knew that Derek would be fine eventually. She wanted her other brother to get his happy ending too.

"Yes." Addison told Amelia as she wiped the tears from her eyes.

"Then go get him." Amelia told Addison. Addison looked at Amelia, shocked that she wasn't getting her ass kicked for hurting Derek.

"I'm hurting your brother." Addison pointed out.

"They both are my brothers and I want one of them to get a happy ending." Amelia told Addison. Amelia had always thought of Mark as her second brother. Mark had been a fixture in the Shepherd house for as long as Amelia could remember.

Addison took a deep breath and stood up. She was still feeling kind of shaky but she wanted to, as Amelia put it, go get him.

"Thank you." Addison told Amelia. The thank you was for a lot of things but most of all for helping Addison realize that she had to make a choice and that chose wasn't the one people thought it would be.

Addison had a feeling that she knew where Mark would be. The Shepherds had a big tree in their backyard and Addison knew that Mark went there when he needed time alone. So as soon as she had closed the door behind herself and Amelia, she went to the backyard, feeling the snow melt under her feet as she walked towards the tree. When she saw his back, Addison smiled. She knew this was the moment of truth for both of them and for the rest of their lives.

"I pick you Mark." Addison whispered from behind him. Mark had not expected Addison to follow him out there so to hear her voice was a surprise. He turned around and saw her tentative smile. Her hands were shoved into her Burberry jacket pocket as she walked over to him. Mark hadn't expected her to pick him over Derek. He had been positive that he would have to watch from afar as the love of his life married his best friend.

"Really?" Mark asked uncertainly.

"Yes." Addison confirmed without a moment's hesitation.

Mark smiled at her as he held out her arms for her. Addison walked straight into his arms and Mark closed his arms around her and pressed a light kiss to her nose.

"It's you Addie. It's always going to be you." Mark murmured as he buried his nose in her hair. Addison couldn't believe that she had actually done it. She had picked the guy that she truly wanted rather than the guy she would have picked when she was a child and dreaming of princes.

"I love you." Addison whispered.

"I love you too and I want to make a life with you." Mark told her seriously. Just then the sky opened up and rain poured down on the new couple. Instead of running for shelter, Addison looked at Mark.

"Kiss me." Addison told him. She had always wanted to be kissed under the rain and Derek would never do that. He always wanted to find shelter before he kissed her. He lacked the spontaneity that Addison craved.

"Always." Mark told her. He pulled her closer to him and leaned down and brushed his lips over hers. It was a soft loving kiss, nothing like the kisses they had been sharing in secret for nearly three months. Addison decided that this kiss was much better. She was not looking forward to telling Derek that they were over but she was looking forward to spending a lifetime with Mark.