Title: Age Is Just A Number

Disclaimer: Grey's Anatomy and its affiliated characters do not belong to me. I mean no copyright infringement.

Summary: What happens after Mark comes back from Los Angeles? What will Lexie do when he tells her his true feelings? Mark/Lexie

Spoilers: All episodes through 6x11, Blink

Chapter 1 – "Don't you want a family?"

Mark sat in the back of the taxi, his eyes staring straight ahead. The taxi driver was talking about the weather or something that Mark didn't care about, so he ignored him. Mark couldn't clear his mind enough to think about the weather. All he could think about were the events of the previous days. It was like a list of what not to do in life. First, he found out that his teenager daughter, who he had just met weeks before, was having a baby that was in danger of losing his legs. Second, he stopped a surgery that would have helped the baby, but could kill his daughter. Third, he made a selfish decision and lost Lexie, which was the hardest thing he had ever done. Fourth, because he lost Lexie, he slept with Addison and suggested that he move his entire life to be with Addison to raise the baby. Fifth, he almost lost his daughter and the grandchild he wasn't sure he was ready for. Sixth, after finding out that his daughter and grandchild were going to be fine, he broke Addison's heart by telling her he didn't really want her. Yes, it was a very bad, very long list. And, the worst part was, at the end of it all, he was alone.

Completely and utterly alone.

He had no one. Not Sloan. Not Addison. Not a tiny baby to hold in his arms. And most importantly, he didn't have Lexie. He had lost Lexie. That was the part he just couldn't deal with.

"Sir? Sir?" The taxi driver called out, pulling Mark out of his depressive thoughts. "We're here."

Mark looked out the window and saw his apartment building in front of them. He watched the meter on the taxi go up another twenty cents as they sat there. He should go home. He hadn't been home in days, but he knew that his home would be empty and that depressed him anymore. He realized he had three choices. He could go in and see if Callie was home and complain to her about everything that happened. He could go home and suck down the bottle of vodka that he knew was in the freezer and drink himself until he was unconscious. Or he could go to a bar and go home with a random stranger. As Mark stared at the apartment complex, he realized he didn't want to do any of those things. None of the choices would give him what he wanted. He wanted her. She had changed him. She had made it so that he didn't want to go home and get drunk or have sex with random strangers. She had made him want her. To Mark, that was a scary thought.

"Sir?"

"I've changed my mind."

"Excuse me?"

"I want to go to 49 Baker Street," Mark stated.

"It's your dollar," the driver said as he pulled away from the curb.

Mark settled against the back of the seat, counting down the minutes until he would see her again.

*****

Mark stood on the doorstep. He knew she was in there. He knew it was the only place she would go. He knocked on the door and waited, holding his breath. The door opened seconds later. Derek stood in front of him.

"Mark."

"Is Lexie here?" Mark asked, pushing past Derek and into the hallway.

"She's still at the hospital," Derek answered, closing the door behind him. Derek knew right away that something was wrong. He could see it in Mark's eyes.

"So she is staying here?" Mark questioned. It hurt him to think that she had moved out while he was gone.

"She said that it would be temporary," Derek explained. Mark was hopeful. Maybe temporary meant that she was missing him as much as Mark was missing her and that she'd want to come home. "She said she would start looking for a new place."

Mark's glimmer of hope disappeared. He glanced down at his watch. "Her shift was over two hours ago."

"You memorized her schedule?"

Mark turned to leave. If she was at the hospital, he would go to the hospital.

"How's Sloan?" Derek asked.

Mark stopped in his tracks and turned back around to face his best friend. He had almost forgotten why he had gone to Los Angeles in the first place. He had gone to help his daughter.

"She's fine," Mark answered.

"And the baby?"

"Fine."

"How about you?"

Mark opened his mouth, ready to tell Derek that he was fine, but then he realized who he was talking to. Mark and Derek had their problems and their differences, but they were still friends and if Mark couldn't have Lexie at that moment, he needed a friend.

"I made a mistake."

"Besides breaking up with Lexie?"

"Yeah, besides breaking up with Lexie. What did she tell you?"

Derek shrugged. "She said you wanted to help Sloan raise the baby and that she wasn't ready for that responsibility so she broke up with you."

"That about sums it up." Mark paused and looked around. "Do you have any boos?"

"You don't need alcohol, Mark," Derek replied. "So, back to this mistake you said you made…"

"I slept with Addison."

Derek was taken aback. He didn't know what to say. He was surprised, but he didn't know why. Mark and Addison were like magnets that couldn't stay away from each other even though it wasn't in either of their best interests.

"Are you going to tell Lexie?"

Mark ran his hand through his hair. "I don't know. But I do know I need to see her."

"She had a late surgery, but she should be home any minute." Derek paused. Meredith had given him strict instructions not to get involved with what happened between Mark and Lexie, but he couldn't help it. Mark was his best friend and he had never seen him look at another woman the way he looked at Lexie. "She's staying up in her old room."

"The attic?"

"It's the only space we have right now."

"Don't you have like two extra bedrooms?"

"It's a long story."

Mark shook his head. He never could understand the revolving doors of people who lived in Meredith's house.

"I'll wait upstairs for her."

Mark wanted to go to the hospital to find her, but he knew that wasn't the place to talk to her. He didn't want to open his heart up to her in the middle of the hospital hallway or in an on call room. He headed up the stairs to the familiar attic. He hadn't been up there in a long time, but it hadn't changed. There was just less stuff in it. Mark realized that most of Lexie's things were probably still in his apartment. In a small way, that gave him hope.

Mark was about to take a seat on the bed and wait for Lexie when he saw a picture frame face down on the bureau. Mark walked over to it and picked it up. It was a picture of them together from Joe's bar. Mark's arm was around Lexie's shoulder and they were both smiling as if they were the two happiest people in the world. Mark loved that picture. He continued to stare at it when he heard the door open.

Lexie walked through the door, but didn't see him. Mark realized he was hidden in the shadows and that's where he stayed. Mark took a moment to look at her. She looked miserable. She seemed paler than usual and her eyes were red and puffy. It looked like she had been crying and hadn't slept well in days. Mark was about to open his mouth and announce his presence when Lexie took off her shirt. She balled it up and threw it on the floor angrily. She didn't care about her shirt or anything else for that matter. She just wanted to go to bed and sleep and never wake up until she could make it through a day without thinking about him.

The next thing to go was Lexie's tank top. Mark quietly watched her, unable to take his eyes off of her.

"You look beautiful," Mark said, stepping out of the shadows.

Lexie jumped.

"Goddamn it!" She shouted.

"Sorry, I didn't mean to scare you," he replied.

Lexie reached for her T-Shirt on the ground and covered herself up with it.

"Why are you lurking in the shadows watching me undress?"

"It's not like I haven's seen it all before." He was trying to joke with her, but she just rolled her eyes. "Sorry."

"How did you get up here?"

"Derek let me in," he answered.

"When did you get in?" Lexie asked, averting her eyes away from him. She pulled the shirt over her head.

"Just now." His answers were short as he tried to compose his thoughts. He hadn't really taken the time to think about what he was going to say to her once he finally found her. Now, he was out of time.

"What are you doing here?"

"I…I wanted to talk to you."

"You could have called."

"I know, I'm sorry. I had to see you."

"How's Sloan?" Lexie asked. She was trying to steer the conversation away from her. Talking about something else made it easier to talk to him. "Was Addison able to do the surgery?"

Mark nodded. "There were some complications, but both she and the baby are going to be fine."

"That's good."

They were both silent. Mark had so many things he wanted to say, but somehow he couldn't form the words. Lexie, on the other hand, was having difficulty blinking away her tears. She had broken up with him, but it hadn't made it any easier. The fact that she had slept with Alex as a way to cope with the break-up wasn't making it any easier. She felt guilty and scared and alone all at the same time. Seeing Mark wasn't helping.

"Lexie, I…" Mark began, breaking the silence.

"What are you really doing here?" Lexie asked, finally meeting his eyes.

He took a deep breath, ready to tell her the truth. "I want you back."

Lexie looked down at the ground. Those had been the words she had been longing to hear, but hearing them didn't make anything better. It only made it harder.

"Mark…"

"Just hear me out…"

"No."

"Excuse me?"

"I said no. Look, you made a choice. You chose her and…and at first I was angry, but she's your child and I can't be angry about you choosing your child over me. I respect you and your choice and what you're doing, I really do, but I can't do it with you. I can't be a mother or a grandmother or whatever it is that you want me to be. I love you, but I can't."

"I don't want you to be a mother or a grandmother or whatever to my kid's kid."

"So…what? Sloan and the baby are going to move into your apartment…"

"Our apartment," he corrected.

"Your apartment," she continued, "and I'm just supposed to ignore them? I'm supposed to look the other way when the baby needs his diaper changed or when he's screaming at two AM? It won't work, Mark. And if we try it, if we're so blinded by our feelings to think that our relationship will work with a baby and a teenager in the mix, all that will happen is that we'll end up hating or resenting each other."
"I could never hate you."

She ignored him. "I won't do that. I won't put ourselves in that situation. The best thing we can do is split amicably and go on with our lives."

"Do you want to split up?"

"Mark…"

"If it weren't for Sloan and the baby, would we have broken up?"

Lexie sighed. The obvious answer was no. They had been a perfectly happy couple. They enjoyed each other's company, made each other laugh, and the sex…the sex was unbelievable.

"I don't know what would have happened if Sloan hadn't walked into the ER that day, but the bottom line is she did and we can't just pretend she didn't. She's a part of your life now. And considering she's living with you and will soon have a baby who will also be living with you, she's a very big part of your life."

"There won't be a baby living with me."

"What? Did something happen? You said the surgery went well…"

Mark put up his hand, stopping her before she continued rambling. "The baby is fine."

"Then what…"

"Sloan's decided to put him up for adoption."

"Oh." They both paused. Mark still hadn't really come to terms with Sloan's decision. "Are you ok what that?"

Mark sighed. "It's her decision."

"But are you ok?"

Mark didn't know how to answer. It would be easy to say that he was fine with the decision, but he couldn't lie to Lexie.

"I never thought I wanted a baby. And then…years ago when…"

"When Addison got pregnant?"

Mark nodded. It still pained him to think about the baby he never had.

"I started thinking that maybe I would like to be a father. But then she had the abortion and the thought of being a father just never occurred to me again after that. And then Sloan finds me and it turns out that I've been a father all along and then when I found out she was having a baby, I thought, this is my chance. This is my chance to be a father. I was so all consumed with that thought, I let everything else go. I didn't stop to think how it would change my life and the lives of everyone I cared about. And I didn't stop to think that this baby wouldn't be mine. Sure, I could help raise it and I could be there for it, but this baby wouldn't be mind. So, am I thrilled with the fact that she's giving her baby up for adoption? No. But maybe it's the best thing for everyone involved."

"I know this must be hard for you, but you'll still have Sloan. You can still be a father. You'll just be a father to a really obnoxious teenager."

He smiled. "She's going back to live with her mother."

"What?"

"I put her on a plane this morning. She realized that she wanted her mom more than she wanted me."

"Oh Mark. I'm sorry."

"Don't be. Being with her mom is what's best for her…and me." He took a deep breath. "You said you still loved me. If that's true, come home, Lexie."

She shook her head. "It's not that easy."

"Why? Why can't it be that easy?"

"Because there's more to it than that."

"What more could there be? Without Sloan, everything can go back to normal."

"No, it can't."

"Why?"

"Because you can't just turn back time."

He obviously wasn't getting anywhere so he decided to change his tactic. If he wanted her back, he was going to have to admit everything he had ever felt for her.

"We're good together, Lexie. We're better than good. You…you changed me. You made me want to be better. A better doctor, a better lover, a better man. I've never felt this way before. I never thought I was the type of guy to settle down and want to be with just one woman and want a family, but I want to grow old with you, Lexie. I want to start a family with you."

"This is exactly what I mean," she replied, ready to cry. She wanted to go home with him. She wanted to get back together, but she knew that wouldn't solve anything.

"What is? Don't you want a family?"

"Of course I do, Mark, but…"

"But what?"

"But you want a family now. You're ready to start a family. You have your perfect career and now you want that perfect life to go with it. And I understand that, I do, but I'm not there yet. I'm still creating that perfect career. I'm not ready for a family."

"Then I'll wait. What do you need? A year? Two years?"

"You can't just put a timeline on it. I can't say that in two years I'm going to be ready to have a baby with you. I just can't. We're at two different stages in our lives."

"So?"

"So…if we get back together, how long will it be before this comes up again? How long will it be before you are tired of waiting for me to want a baby? Then we'll be right back where we started. And that's not fair to either of us. If you want a baby, if you want a family, you're going to have to find someone who wants the same things at the same time."

"What are you saying?"

"I'm saying for the first time since we started this relationship that our ages are working against us. We had fun, Mark, but this won't last. And it's unfair to think that it will. I think we both just need to move on."

"Is that what you want?"

She nodded. "Yes."

"Well, then I guess there's nothing else to say," Mark said. It wasn't exactly what he had in mind. Somehow he had envision himself waltzing in and sweeping her off her feet, but that's not what happened and he was going to have to live with the fact that he had possibly made the biggest mistake in his life.

Mark turned to leave the room.

"I'm sorry," Lexie said barely above a whisper.

"Me too," Mark replied before leaving the room.

Author's Note:

Ok, so this story is certainly not the best story I've ever written, nor is it my favorite story I've ever written, but this is a story that I felt like I had to write. After watching last week's episode, I was so torn up over what was happening between Mark and Lexie that I just had to get my thoughts down on paper. So, I hope you liked it and there will be more chapters so stay tuned! Thank you for reading and please don't forget to review!