It was a oneshot, I swear. But you guys wanted Derek's reaction, and I was bored, and this happened. Utterly unrealistic, I know.

Enjoy.

"I slept with Mark." "I'm being considered for Chief."

Even in the end, they overlapped. Words bleeding into each other, drowning each other out.

He let the door slam shut behind him, the sound ringing in his ears with her words.

I slept with Mark.

Be mine he'd said to her, when he knelt in front of her that soft summer evening. On this very corner, actually, just outside St. Luke's Garden.

She'd wanted to go to the church because they made it , they finally made it, they were doctors - any church will do, I'm a WASP and we only actually go to church on Christmas - and it was the day before graduation, end of summer in the air, the beginning of fall. The beginning of change.

He tugged her into the little garden afterwards, there were butterflies and flowers and it was so perfect he almost stopped because it might have been too cheesy and she's not cheesy but the ring was burning a hole in his pocket and after tomorrow they'd have no real reason to stay together. He wanted her to be officially his.

So in the shade of an oak he'd knelt and asked her; be mine, and when she pulled him to his feet she stumbled a little and said I always was.

Not anymore.

He catches his reflection in a plate glass window and he knows he's vain but he looks okay for someone who's been through what he has tonight. Why did she do it?

What does Mark have that he doesn't? Mark was always the needy one. The surrogate Shepherd. He needed their love and their protection and their warmth and he soaked it up greedily, couldnt get enough, even as he himself ran in circles trying to avoid it all.

Wasn't it enough? Did he have to worm his way into this most private of relationships as well, steal what was never meant to be his?

He staggers against a metal trashcan, bile rising in his throat as he pictures them together...where? The office? His or hers? An on call room , that would make sense. His monochrome penthouse, as colorless as she is vivid. Their home. No.

The possibilities dance through his mind in sickening Technicolor as unworried pedestrians pass him by - just another drunk on a Sunday night. He finds another on the next street corner where she'd pressed him up against the signal post to kiss him, the new diamond on her hand scratching behind his ear.

The man stares hollow-eyed at him, taking in the calfskin jacket and leather shoes, obviously confused. He peels the jacket off - last year's birthday gift from her.

"Have it." he says, and the other man accepts.

Did he do the same with her? Push her to Mark? All the canceled dinners and forgotten birthdays and anniversaries...did he do this?

But why would she pick Mark? It could have been anyone at all, she turns heads wherever she goes. Was it as random as this drunk he's chosen? Because he was simply there?

Mark,though. His best friend. His brother. He actually said it to him once, they were about thirteen and he was particularly overwhelmed by the wave of Shepherd sisters and he'd whispered fiercely to Mark in the dark of the room they were sharing - you're my brother ,Mark. He doesn't recall what Mark said. If he said anything at all.

It's late, dark and getting cold and his phone buzzes in his pocket. Addie, the bright little screen says, Addie.

He called her Montgomery first, that day in the lab, peering through smudgy goggles and gagging on formalin. Hey Montgomery, you want to go first?

She did. She always likes to be first. First in med school, first solo surgery. Chief Resident. First to get a fellowship. First to make attending, a full week before him. First to break their vows.

He's thought about it, he won't lie. They've been ... distant, for a while now. She works as much as he does but her specialty doesn't drag in as many emergencies as his does and she's home more often. She used to wait, curling on the sagging couch in his office they'd christened with giggles and muffled moans, wait for him to finish and tuck her arm into his as they left.

There was the blonde resident in his OR, the pretty blue eyed neuro fellow, the fresh face d candy striper, the nurse, the receptionist at his practice. But he only thought. She acted. Always first.

And then he called her Addison, Addisonwouldyouliketogetcoffee. She said yes, and then people were calling them AddisonandDerek. He liked it the other way round, but whatever.

And then he called her Addie, because saying her full name took too long, he teased her. Addie, short and sweet , two things of which she is neither.

His ring finger feels bare, light, but his feet are heavy and his legs ache but he savors it because it's the slightest distraction. The skin where his ring used to sit is a shade paler, unchanged from eleven years ago whereas the rest of him is different.

His phone has stopped ringing.

He could leave. Go somewhere new, start over. Clean slate, rewrite himself. She's written so much of who he is that he feels like he won't be much of anything if she's gone.

Fifteen years they've been together. Thirty five years he's known Mark. He knows them inside out. The good and the bad and the dirty and the ugly and the deepest secrets that only make appearances drenched in alcohol.

How didn't he see this coming?

Or did he? Was he too busy to notice? You work too much they all say. His mother and his sisters and his wife.

But that's how he made it here, the youngest Chief candidate. His work has paid off. He didn't realise it would cost him his marriage though. Because it almost certainly has.

He can't look at her now, can't think of her, not without imagining Mark's hands burned into her, her perfume on his skin. He's always been possessive and he knows it, he's the guy who gets surly at bars when men stare at her. She used to think it was sweet. Don't worry, she'd say, you're stuck with me.

Stuck. He's still stuck, here in this city that reminds him of her at every turn. She's everywhere here, a laughing taunting ghost. He opens his wallet to pay for the coffee he's bought and there she is, smiling up at him in miniature. He needs to get away.

What would it be like, he wonders, to just get in the car, drive, aimlessly, let the road take him wherever? He's never done anything as spontaneous before. He's one to plan and plot and deliberate. She's the impulsive one.

She's a lot of things. Intelligent and stubborn and funny - a lot of people don't know that, actually, that she has a wicked sense of humour. She's a worrier, he can imagine her right now, on that couch, shredding perfect cuticles. Or maybe not. Maybe she's gone. She's not a runner, though; if anything she'll cling to the end, dig her nails into what's left of them.

How the hell did she do something so stupid? Screwing his best friend, in his bed. Where she knew he could walk in on them. He realises with the faintest of guilty pangs that he hasn't exactly been home much lately - maybe she thought they'd get away with it. Or maybe she knew they wouldn't, maybe she did it on purpose. In your face, Derek.

He wouldn't put it past her. She's remarkably passive-aggressive. It's something they fight about. Often.

They fight about a lot of things. How he's never home. Why she has to make an issue of everything. Why he leaves his clothes on the bed. Why she leaves her infernal shoes where he'll trip over them. Treatment plans for their shared patients. Dinners with his family- I'm not going by myself, Derek. Who drank the last of the coffee in the pot. Why the hell he can't put the goddamn toilet seat down.

But, he realises, these are things they used to fight about. And then make up. Deliciously.

They don't fight anymore. She might roll her eyes, purse her lips, turn away from him in bed. He might spend inhumane hours at the hospital, not return her calls, spend days without speaking. But they don't fight anymore.

How'd they end up here? They were never like this. They promised to be the fun crazy old couple. They used to be nauseatingly in love, that always-touching, food-sharing, annoying couple.

Used to be.

He used to be unable to go half a day without seeing her. He used to tell her about his surgeries and ask about hers and he used to want to jump her in the hallway. Did, actually, a fair few times, except in on call rooms - the hallway might have been a bit much.

He doesn't know what he feels anymore, he's sort of numb. Anesthetised. It's a defence mechanism. Maybe it's better this way, because he doesn't have to feel the pain at all.

He takes advantage of it, turns his footsteps backwards and finds himself on the top step he'd stood on hours ago, clutching flowers he knew she thought were cliché and full of hope that this would finally turn things around. He hopes she's gone - to Mark, to the hospital, he doesn't care. The house is completely dark. She's probably with Mark. He closes his eyes, blocks out the images .

He left his keys, he recalls dully, in the pocket of the jacket he gave away.

Nothing more humiliating than having to call your cheating wife to leave her lover and come let you into your own house so you can make a dramatic exit.

But the door is open. It swings open easy as anything when he touches it, there's a puddle on the floor just inside the door. He shut it when he left. He's sure he did. He slammed it hard, the way she's always bitching at him not to. It latches by itself, when you slam it.

The door is open and there are no lights on and this is New York after all even if the neighbourhood is ridiculously expensive and she slept with his best friend but still his heart pounds against his ribs as he edges silently into the foyer.

Please no.

"Derek?"

Her voice is rough, hoarse. He swings around to see her huddled on the couch exactly where he'd left her, eyes glittering emerald in the dark.

"You left the door open?" he exhales harshly, frustrated that she still could make him feel this scared.

"I thought it must have shut." she says softly, and he knows the rusty sounds are probably her wiping surreptitiously at her eyes.

It didn't though. It didn't lock even though he slammed it so hard. He gave away his keys. But it was still open. And she's still here.

"You're still here." he observes, his voice hard and unfamiliar.

"I'm sorry." she chokes. "Derek please, I'm so-"

Sorry is a good word for what she looks like right now, crushed roses on her lap, eyes red, hair sticking to wet cheeks streaked with mascara.

"Don't bother." he snaps, the anesthesia starting to wear off. "Where's your lover?"

She's on her feet now, unsteady, damp fingers on his arms." I'm sorry, let me show you how sorry I am-" . She's wearing his ring along with hers. It slides the length of her finger and almost falls off when he pushes at her.

He peels her off and deposits her on the couch. "Don't."

He can't stand the sight of her, is actually afraid what he'll do if he stays. "I'm leaving. I'll be back in the morning, and you won't be here."

She looks up at him, one hand curling unconsciously into the arm of the couch. "No."

The fucking nerve...

"Excuse me?"

"No." she repeats, shaking her head this time. "I'm holding my ground. We don't quit."

"Quit?" he spits. "This isn't quitting, Addison, there is nothing left to quit. We're over."

"I'm sorry, Derek, it was one time -"

"Fuck you, Addison." he laughs mirthlessly "Guess Mark took care of that already, though."

He's hurt her, he's pierced the armor, he can see it in her eyes.

And he's closing strong fingers over her arms, she's so light, barely anything in his arms, sliding a little in the rainwater puddle , salty water on his cheeks and hers, we're AddisonandDerek and it's raining outside and he used to love her. So much.

So they stand there, not sure who's holding on and who's pushing away- maybe they're both doing a little of each - and she cries and he cries and he pulls her back in even as he steps away from the warmth of her body.

"I'll be back in the morning."

She's standing there in the foyer, shaking ever so slightly, eyes huge. "And..."

"And you'll still be here." he says, half question, half order. "In the morning?"

She nods. "We're not-"

"We're not over." he admits. "Not yet."

She offers a tiny smile. " We're still DerekandAddison."

Well. He's still Derek, and she's still Addison. Maybe they'll find a way to glue themselves back together.

He gives her a smile in return. Or he tries, anyway, and maybe she sees it because there's the faintest spark in her eyes.

"I'll be back in the morning."

He will.

Gah. How I wish this happened.

I know it's totally tacky to ask for reviews but I'm a bit greedy. It's okay if you didn't like it -tell me about it. Liked it? Tell me about it. Pretty please?

Also I swear I'll update my older fics, I know I'm slacking. I'm just...stuck , at the moment.