Disclaimer: I own nothing, no matter how in love I am with the characters. I am just letting my imagination go for a spin and this is what she decided to drag home.

I understand

By Carla

She can see them.

She can always see them.

She doesn't know if Derek thinks she's blind, stupid or just plain doesn't care. Day after day, they go on like this. Elevators are they favorite space, she knows… she actually understands.

"Hey." He says, smiling the minute the elevator door closes and he notices the woman inside.

"Hey." She answers back, smiling.

They keep giving one another this longing looks, the tension and love between them is palpable. Addison hates that the most. She hates it because it makes her feel like a villain, like she stole something from Meredith. Then she has to remind herself that Derek was hers before, for over twelve years, he was her husband. She didn't steal.

She and Derek spent the day at the hospital, pretending everything is alright. The barely cross paths, they never look for each other to rendezvous at some locker room, they don't seek each other to talk about their problems, and they never eat lunch together.

Then again, they never ate lunch together back at New York anymore either. But somehow, it was more bearable there; she felt a whole lot less alone.

"Is this sit taken?" he asked, giving her his most charming smile.

"Only if you take it." She answered, happy to see him.

"And what is a beautiful neonatologist like you are doing at a hospital like this?" he asked, looking at her with those deep eyes of his. She knew that from everyone else, it would be a casual question between two friends, nothing important. But with him it's different, because whenever she looks into his eyes she feels like he might actually know her.

"I was supposed to meet Derek for lunch, but this surgery came up…"

"So he had to go."

"Yeah." She whispered, a little ashamed to have to admit her husband dumped her for a surgery he could have passed on. Then she reminded herself of whom her company was and she knew there was no reason to be ashamed.

"His loss, my gain. Are you going to eat that pudding?"

Meredith is nervous around her these days. She guesses that's normal, after all she's quite obviously in love with her husband. Still, lately they had been trying the 'friends thing'. It was all a pretense and she knew it, hell, probably even Meredith knew it. But if Addison Forbes Montgomery-Shepherd had learned anything at all these past few months of trying to repair her marriage was that, sometimes, the pretense was all that kept you going.

Pretending could actually count for hope? Was it the same thing?

But something was different, ever since prom night. She could guess what, she had been there. She had not said anything though, because she thought she deserved better, she deserves for her husband to come to her and admit he had strayed. She knew Derek and Meredith had given into temptation, she just knew it. She had been there too.

She couldn't help but smile as he tells her everything about the surgery he did today. His eyes were shining like a little boy who is talking about his favorite toy. That's him, he is what he does, and he is passionate about his job. She loved that about him.

They are reaching her house now, the expensive brownstone she and her husband worked so hard to afford, the home they always dreamt about, the place where she waits for him to come late every single night. She was supposed to meet him at the hospital and go to lunch, and as usual, he couldn't make. So, she had dinner with her impromptu companion, who somehow always did manage to create the time for her.

"Thanks for the company." She said sincerely as they reach her doorstep. He's still smiling that dazzling smile of his, his hands shoved in the pockets of his brown leather jacket.

"You are kidding? I love hanging out with you, you know that." She had to smile. He may be an arrogant jerk to everyone in the planet, but to her he's always sweet and caring. He was her shoulder to cry on and one of the few people who could manage to get her to smile and mean it these days.

"Still, you probably have better things to do. Girls to date and stuff." She smiled, even though she felt a little bit sad.

"Nothing beats dinner with a tall gorgeous red-head in most guys' book." She couldn't help it, she had to hug him. She felt his strong arms encircle her body and his forehead was resting on hers now.

What's going on? She asked herself for the hundredth time. Why were their hugs longer all of a sudden? Whenever he would kiss her good-night, she could feel he didn't want it to end. Most days, neither did she. He would call her, everyday, ask what she was doing. She would send him text messages, annoying him through the day. What the hell was going on?

And now, as they hugged, she couldn't help but feel the electricity between them, her body was burning on, his eyes were closed, she felt a soft gasp escape her lips. This was never supposed to happen…

But it did happen. So, Addison closed her eyes and didn't stop him as his hands reached for her face, caressing her cheek. She didn't open her eyes when she felt him kiss her cheek softly, and then whispered her name. She didn't open her eyes when he gave a butterfly kiss on the lips. She didn't stop him when he deepened the kiss and was surprised about the passion with which she responded to his kiss.

She finally opened her eyes when the kiss ended. Then, she disentangled herself from his arms and run into the brownstone she and her husband bought, where she collapsed to the floor, crying.

Tonight, like every single night, she will go home with her husband. The cheating wife with the cheating husband, maybe the universe did have a sense of irony. She hated irony at the moment. Because at the moment, her life was a big fat lie, she hated her life, she hated herself. And most of the time, she hated Derek.

She hates Derek, because he didn't sign the papers. Derek asked her to stay, when she wanted to go, he said let's fight for our marriage when she wanted out. And she stayed and she fought, knowing neither of them really wanted her to. And what did she stay for? So she could be a witness to her husband's longing stares at his intern, and their freaking elevators.

Sometimes, Derek would joke with her, make love to her and cuddle her afterwards. Other days, he would ignore her and look right through her, like she was invisible, like she was nothing. If there was one thing on the Earth she couldn't deal with was being ignored. She hated the feeling, and looked for a way to make herself feel better. Right? That's who she was. While her husband was working hard building a career and making a name for himself, she felt neglected and like the spoiled girl she was run to the nearest pair of arms. Right? That's what he thought; it was probably easier for him that way.

He had never asked. In all the time they lived together in Seattle, he never asked a thing about her affair. He constantly talk about it, mind you, he would make snide comments and throw her great sin in her face. But he never wanted to talk about it. Why it ever happened? What was she thinking? Did she actually feel anything for Mark? He had never asked.

And that hurt.

What hurt the most, though, was keeping her mouth shut. She was in this marriage, in this hell, in this fight. And Addison Montgomery didn't give up, she was a fighter and a winner and she wasn't giving up even if her husband was screwing Meredith Grey yet again. Maybe she deserved it; she was an adulterous bitch after all. But now, so was he. Still he never asked, because he didn't want to know.

Even though he was a cheater too, he could still look down on her, because it had happened with someone he loved. He wasn't like her; he felt in love, he had a relationship, not an affair. Meredith was someone he loved, while Mark was someone she did. So he was still better. He was sacrificing his happiness and his love to do the right thing and stay with his wife, he was been noble and a good husband. She? She didn't deserve the chance that he was giving her, so she had to wait for his feelings for Meredith to pass, she had to wait while he worked on his issues, and she was the one who had to work on saving their marriage.

Because he loved Meredith, he didn't have an affair.

"I love you, Addison." She felt his hot breath on her neck as they hugged each other. They were resting naked in his bed, she never meant for it to happen but it did. His eyes were clouded and his body was trembling, coming down from their climax. He caressed her face with the back of his hand and kissed her softly in the lips.

"I love you, Mark." She found herself answering. And as she spoke, her heart broke a little. Because it was wrong, because she was married to his best friend, and she wasn't this person and he wasn't either. They were good people and she had a good husband, and she loved him. But as her lips searched for his again, begging for him to hold her, she knew she was not lying. As wrong as this was, she loved him.

Sometimes she hates Derek, because he put them in this nightmare. Sometimes hates Derek for longing after Meredith and disregarding her feelings. Sometimes she hates Derek for looking right through her. But mostly, she hates Derek for thinking he was the only one who sacrificed something important for their marriage, for thinking he is the only one in pain. She had to look into Mark's eyes and tell him she was in love with her husband when both of them knew she was lying, she had to sit at the trailer while Mark waited for her at the bar, eager to whisk her away back to New York so they could build a life together. She let him go, and it killed her.

So, she sees the way Derek and Meredith die a little every single day not being together. She knows they slept together, but she also knows Derek is not strong enough to leave her. And while she hates them both sometimes, she can't resent them.

Because she understands.