Part of you thought maybe you wouldn't see her again. If you didn't, you knew that you'd go through life much in the same way you are now – blinded, numb, sort of uncaring. Sure, you care on the surface – you care about your job. You care about helping people. You tiptoe around Derek because it's easier not to incur his wrath. And you care about Lexie, despite the fact that you slept with her, first of all, just to prove you could.

Life is about proof. It always has been for you. Tell you that you can't, and you'll find a way to prove you can.

When she stepped through the doors, though, when you met her blue eyes, saw that her hair was a little darker than before, her skin a little more tanned – you realized that sometimes half-assed just isn't good enough. It doesn't matter how much you feel like God because you created a skin flap or put someone's broken face back together; she's not there to admire it, to talk about it – even to snark it.

Lexie was, and is, and is willing to provide you the accolades you need. Isn't that enough?

Watching her legs flow into a rhythm as she first hugs Derek, then Meredith, you realize:

No, it's not enough. It's like drinking wine when you could have champagne. Even if the wine is forbidden, it's never as sweet.

//~//

Part of you thought things would always stay the same. Mark was the person you fell back on (and if you want to be absolutely honest, the person who understands you most and best, as well). He was always there – he was there when Derek left; he was there when Derek refused to warm up – he was there through the sham marriage that took place in the cold wet trailer, out in the wilds of the forest. So it wasn't a stretch – it was comfortable. Knowing that when the sunshine got too much, he'd be there, waiting behind the rain.

You find out later from gossip in the OR that he's not actually waiting, anymore. He's dating an intern.

Now, this really isn't surprising, in the grand scheme of things. You've really got no right to be upset, or to feel anything other than indifference. Your rational mind tells you – you left, and he had every right to move on.

She's dark-haired, petite, always smiling. Very much different than you. You wonder if she's as good in bed; she looks so delicate that she could break.

You notice she has tics that you don't – she plays with a piece of her hair when she's asked a direct question. She bounces a little on the soles of her feet. She's eager and full of energy, and you know that at the end, you weren't.

It's not really fair to expect him to wait.

It didn't stop you, anyway.

//~//

Derek gave you permission to sleep with Addison. You're actually a little taken aback.

"Excuse me?"

"I said, you can have her. I don't care anymore."

"Really." It's not a question, but Derek takes it like that, and he turns to stare you right in the face.

"You love her. I don't know why I didn't see it, but it could be because the two of you snuck around behind my back. That tends to cloud judgement just a little, you know." His voice is satirical, but you don't blink.

"Okay."

"Is that all?"

"Well, Derek, what do you want to hear?"

His eyes twinkle a little. "A thank you would be nice."

You feel like punching him, but don't bother. You wonder what he would think if you told him you'd been sleeping with Lexie, though he forbade you to; would it wipe the sanctimonious smile from his face?

"Okay." You don't say anything else, and get up to leave.

Derek looks confused, but shrugs it off.

Later, while lying in bed beside a sleeping Lexie, you think about his offer, and snort a little.

He never knew her – he never knew her at all.

//~//

You find him kissing his intern in the corner of an on-call room and after quickly backing out, you change your mind, and charge in.

"What are you doing?" you demand, as if you have a right to know. You're not sure what makes you so possessive, but you feel as if he should be telling you these things. You feel even slightly betrayed, even though you know it's stupid.

He just laughs while Lexie cowers a little. Then, he deliberately turns and kisses Lexie square – deeply, even. She practically melts against him (well you know the feeling!) until he pushes her gently towards the door and turns to face you.

"What the hell do you think you're doing?" There's a hint of amusement in his voice, but it's mostly pissed off, and you can't blame him.

You slump back against the wall, the feeling of the cold cinderblock against your back the same as it was a year ago, when you stood in this very same room as he.

"I'm sorry," you blurt, but then shake your head. "Actually, Mark, I'm not sorry. Who is she?"

"That's really none of your business," he replies, his voice still casual, but holding a note of warning now – warning you to watch your step. You're not together – and you're stepping over the line.

You charge over it, anyway. "I miss you."

"You don't miss me. Stop lying."

You've vowed not to break down in front of him, but Seattle tends to bring out the emotion in you, and your lower lip trembles, anyway. "I do miss you."

"Derek gave me permission to sleep with you."

"What did you just say?"

"I said, he gave me permission to sleep with you. As if I've ever needed it," he adds, his voice sarcastic. "I pretty much do whatever I want."

"You always have," you mutter, and then see sudden red. "What did you even say to that?"

"I said, okay."

"That's it?"

He pushes a hand through his hair, and you notice that it's greyer than it's ever been – the black of his hair frosted over. You long to touch it – just in that moment – but something about him makes you keep your hands at your sides.

"Addison. You left. What the fuck did you expect me to do?"

"I don't know," you reply miserably and slump against the wall. You don't want to tell him what you hoped, but you know he knows anyway.

He takes your shoulders gently, pulls you close. "I loved you."

"Past tense?"

"Well, yeah." He doesn't offer any other explanation, but you push anyway.

"What changed?"

He doesn't reply for a moment – but he keeps holding you. Your face, tear-streaked, wets the front of his scrubs, and you feel his hands on your hair, stroking it back.

"You changed. You didn't want me. I'm not a masochist, Addie. I wasn't going to wait around forever."

"I did want you." Your voice is muffled against his scrubs.

"No, you didn't. You wanted someone to make you feel better. And I can do that – as a friend."

"Don't you want me?"

"Of course I want you! But that's not what you want."

"So who is she?"

He sighs deeply – you hear his chest rattle a little, wonder briefly if he's getting over a cold. The truth is, he's started smoking again because Lexie's just that hardcore in bed, but thankfully, he doesn't say that to you.

"She's Meredith's sister."

"Meredith Grey?" You pull back from him for a moment; look up into his honest blue eyes.

"Yep."

The words hang unspoken in the air – is she as good? Does he care about her like he did about you?

"I can't, Addie." He sighs again and you lay your ear back against his chest, hear his heart beat strongly and slowly, soothingly, even.

"I know." Your voice is small. "What does Derek think?"

"Derek doesn't know."

It's then you pull away. "So you're pulling this shit again, Mark?"

"In a matter of speaking." His face is slightly guilty and you suddenly feel like an idiot for thinking he wanted you for any reason other than to pull one over on Derek.

"That's why you don't want me anymore," you snap. "Because he told you that you could have me. Fuck, Mark!"

You storm to the door. "Fuck him. Honestly. And fuck you, too."

With that, you let the door slam behind you, studiously ignoring his hurt face.

//~//

She's yelling into his face – you know, because you followed her, despite your better judgement. It's not a conversation you feel you have a right to hear, but curiosity always killed the cat in your case and you followed her in anyway.

Her hair lifts from her shoulders, whirls around her head as she shakes it in disbelief, staring into his face.

"Here's point number one, Shepherd. You don't own me. I don't know what gave you the idea that you did. You're a misogynistic bastard – how DARE you give permission that anyone can 'have' me?" Her voice is shrill, but Derek doesn't pull back. He does, however, wince.

"You misunderstood me, Addie."

"How did I misunderstand? That's what Mark told me – that you gave him permission to sleep with me. As if you ever could control what I do!"

Derek sighs – another point of his taken out of context. "I thought he loved you – and you loved him! You seemed to, anyway. And so did he!"

"What the hell does that have to do with anything? You're not my father, Derek; you don't get to give your blessing here. I will do whatever I want and so will Mark – without your permission!"

"I just wanted you to be happy," he sulks, and you know innately, that it's true. He never did want to create any drama. He's just not smart enough or humble enough to express it in any way but pompously.

Addison, however, isn't buying it. "I don't give a damn what you wanted or thought. When you divorced me, you gave up any right to my happiness or my well-being. Just the same as I gave up any right to you."

"I'm sorry."

"You're not sorry. In the future, Derek, stay the fuck out of it. You don't own me and you don't own him!"

"You don't own him, either."

"What does that have to do with anything?"

"Addie, why are you back here? Really?"

"To sabotage your happiness with Meredith – what else?" Her voice could peel paint off the walls, and you wince simultaneously with Derek.

"Seriously."

"Seriously, Derek, I'm here for work." It's a bald-faced lie – that's not the only reason she's here – but he buys it.

"I am sorry," he tries again.

Her face softens for a moment. "Just – don't, okay? You don't get to make decisions about me. So keep me out of it from now on."

With that, she turns to leave. You skulk off in the other direction, but you feel ready to explain. She never really leaves your head – you're never sure you really want her to.

//~//

You wonder exactly what his motive is with Lexie. Obviously, he's not thinking about you. But does he remember anything about you? When he's sleeping with her, does he ever picture you? You're engaged in these masochistic thoughts when he rounds the corner of the hospital and finds you sitting on a bench just outside the doors.

You smell cigarette smoke on him. "I didn't know you still smoked. You quit years ago."

"Yeah, well." He doesn't offer any explanation, and this time, you don't push him. You swing your leg back and forth, absently admiring the weak sun on the Prada buckle, when he speaks.

"She's not anything like you. She's totally different."

"Really?"

"Really. She doesn't laugh like you. She doesn't have an obsession with designer shoes, or have a trust fund, or enjoy the same things as you. She's young, and she's in it for the sex. That's all."

You open your mouth, and then close it, but he catches your eyes anyway. "I do love you. I probably always will. But Addie, you can't expect me to put my life on hold for you."

The tears are back, but this time, your tear ducts aren't too proud to let them fall. He reaches out, wipes a tear from your face. "You don't get to be upset about that. You made your choice."

"She's standing where I used to stand. I can't help but regret that she has a place with you now."

"You didn't give up all places with me just because you left. You just don't get to assume that you can come back and find me unattached and waiting. But I'll always be here for you."

He hugs you then – strong, bear-like Mark, and you lean against him. It takes some getting used to. You're not sure you're okay with it.

But she who dares to stand where you stood – you know that she'll have some big shoes to fill in his heart.

Maybe, that's enough.