A/N: Hi. So. I love every single one of you and I love and appreciate every single review asking me to update my WIPs. I promise, they are in progress and many (including The Climbing Way) are very very close to post-able. But I've been traveling so I haven't had the time/space to work against my outlines and all the drama I bring to the WIPs. The upside? I've been traveling and let's just say Addison's not the only one who ... enjoys ... planes, trains, and automobiles. So here's the result of a few hours of travel, and frankly, the most surprising thing should be that I've never written this scenario before.

This started out as a flip the script idea, but it's a little much for FTS so: here we go. Crossover, Addison and Derek are fighting about his patient because he's being an ass, but instead of Addison just standing there taking it when he yells at her, she fights back. And then the rating increases. This is a strong T with warnings for post-divorce nakedness and angry-stress-relief coupling. (If you think it's too much for T, tell me and I will take that into account!) This won't be everyone's cup of tea, you've been warned. Enjoy (I hope)!

You're a good doctor. So am I. Let's just be good together.
–Derek, An Honest Mistake

"Look, it's not that complicated," he snaps. "Either the baby's going to die, or he's not. Either the mother's going to die, or she's not."

Addison stares. She made it onto the catwalk in time to relieve Karev as Derek snapped at him, but she's certainly not prepared to bear the brunt of her ex-husband's frustrations herself either. She's exhausted, overtaxed, and seriously doubting her decision to get involved with a patient who's obviously gotten under Derek's skin.

I'm sorry, we're divorced, how exactly did I end up back on a catwalk with you taking out your problems on me?

She glances at the intern, who doesn't need to be involved. "Would you excuse us for a moment?"

Karev takes his leave quickly – she can't blame him – and then she turns back to her ex-husband.

"Look, I have been up all night too and I don't appreciate you yelling at-"

"My patient!" Derek cuts her off with an angry hiss. "My patient. Let me know when the damn test results get in."

"Derek!" She grabs the sleeve of his lab coat, tightly, before he can walk away; with the element of surprise on her side, she tugs him with her off the catwalk.

"Look, Derek, I know you're frustrated but you don't get to take it out on me. Not anymore. We're not married."

"Thank god for that," he mutters, and she hates that his words make her stomach clench with hurt.

"We're not married," she repeats with as much dignity as she can manage, "which means you will treat me like a colleague – civilly, with respect – in this hospital, do you understand me?"

He blinks, not doing a very good job at covering up his surprise. "Just get my damn test results," he repeats finally.

"You asked me to get involved, Derek. I'm doing you a favor. And I will turn around right now if you keep acting like such an ass."

"No, you won't," he says immediately.

"Yes, I will if you keep treating me like this, Derek, I will get on a plane with Archer, you have no right and it's about time you actually – Derek," she snaps, because he's gripping her arm now and dragging her around the corner. She pulls her arm away from him and he grabs it again, yanking her closer.

"You're staying, Addison," he says urgently. "My patient needs your help."

"Let go of me," she says evenly, meeting his eye.

"No. Not until you say that you're staying."

"What is this, kindergarten? Derek."

But he's staring at her in a way that makes her feel like this is definitely not kindergarten, and she shifts uncomfortably.

"You wouldn't leave a patient behind who needed you," he persists. "You know you wouldn't. Say it."

"I will," she insists, "I will leave if you can't behave like a civil person, Derek, and stop taking everything out on me."

He can't hide his surprise at all now. Is it California, the beach-dancing and the sunshine, that's making her act like this? Derek's not used to being pushed. He's not expecting anything except gratitude for Archer and falling in line for his patient like he told her to do. His patient. He's sick of her fighting with him instead of helping his patient. His patient, his timetable. Period.

"You're wasting time," he tells her coldly, taking a step forward.

She raises her eyebrows, braced against the wall now. "You know what? You're right. It was a waste of time to stay here – when I can be on the next plane out of here, and you can deal with your patient yourself."

Suddenly the wall behind her is giving way, or was it a door? Now they're in an on-call room she hadn't even seen. He shoves her inside and stands in front of the door, arms folded.

"Don't you dare threaten my patient," he says sternly.

"Your patient." She shakes her head. "How about you don't threaten me? How about that?"

"I did what you wanted!" He pushes a hand through his hair, aggravated in that way only she can make him. "I saved your ass of a brother and now you're going to help my patient – what the hell do you think you're doing?"

She's reaching around him for the doorknob, or trying to.

"Leaving," she says with the coolest dignity she can muster. "Move out of the way, please."

He meets her eyes. "No."

She props a hand on her hip. "What do you mean, no?"

"I mean … no."

"You are impossible!" Now it's her turn for a gesture of frustration, throwing her hands in the air. "You can't just blame me for everything that goes wrong, beg me to stay and then turn on me, you don't get to treat me like that, Derek, not anymore, I don't care what you did for – " but then suddenly she's not talking anymore because his lips are on hers, rough and bruising, and he's somehow reversed their positions so she's the one pressed against the locked door.

"What the hell?" She pulls back with some effort, running one shaking hand across her mouth. "Derek…"

He's staring at her like it's the first time he's seen her. "You cut your hair."

"You just noticed." She shakes her head, lips still tingling. "You're unbelievable."

He's studying her closely, making heat rise in her cheeks. "What?"

"I don't know if I like it," he says, sounding like he's considering the question, and she raises her eyebrows.

"Well, I don't think your opinion actually – " but she stops talking because he's buried both hands in her shorter locks and yanked her head back.

"Less to hold onto," he smirks, and then his lips and teeth are on her jaw and she makes some effort to move away from him – sort of – but then his mouth is on hers again, rough and insistent, and damn it if he still doesn't know exactly how to get to her –

"Derek," she pants his name urgently when he gives her a moment to breathe, but his hips have pinned hers against the door and maybe she might as well just let him work out some of his frustration if he's so insistent on it. It's a … favor, that's all.

"Tell me to stop," he suggests, pulling back from her.

Their eyes meet, a challenge. Damn it.

She says nothing.

"Thought so," he smirks, and before she can process how annoyingly pleased with himself she looks, he's yanking off her jacket and then growling with frustration when he's reminded she's wearing a dress underneath it rather than a skirt and top.

His expression amuses her, which annoys him, and he shoves his hands between her body and the door and drags the back zipper down so hard she's worried he might have ripped the fabric.

"Be careful," she snaps.

"Why?" He looks confident again. "Afraid you'll make it too obvious how you like to solve your problems?"

She'd take a step back, but she's still backed against the door. She settles for glaring at him. "Screw you," she says evenly.

His eyes darken. "I hope so." Shoving her dress off her shoulders, he grabs rough handfuls of soft flesh; she cries out and he swallows the sound in another fierce kiss. She's given him too much ground; two can play at this game so she tangles her fingers in his hair, pulling harder than she would normally and biting down on his lip, hard.

He pulls back with a pause, touching his mouth, and then a wicked grin. Then he steps back from her. "Door's open," he taunts her.

She doesn't move.

God, they're fucked up.

For a moment they stare at each other, and then he shoves the skirt of her dress up; it's so like Derek, he's not going to undress her, not when it's like this, that would be too intimate, so her dress becomes an awkwardly rolled bunch around her waist while everything he needs is exposed. He nods with satisfaction and then grabs both thighs, pushing her none too gently up the wall so he can pin her in place like a butterfly, rolling his hips against hers until she thinks she might faint. The problem is that he knows her body too well, and her face too, so pretending this isn't affecting her won't work at all.

"You're not leaving," he smirks. "You're not going anywhere."

"We'll see," she manages.

"Yeah, we will." He surprises her by shoving the bunched up dress over her hips to puddle on the floor. Dragging her against him, he tastes everything from the arch of her neck to the fragile satin cups in the way of his journey, warm insistent mouthfuls that threaten to leave marks, that make her push on his head to no avail and finally sink back against the door because god, she hasn't –

"Derek," she snaps, and finally he looks up, satin between his teeth, and she scowls at him. "Don't leave marks."

"Why?" He releases the fabric from his mouth and makes short work of it, dragging the material off her arms and tossing it out of reach. "Who's looking?"

It's certainly true and it's also surprisingly painful even if he didn't mean it that way, but she has no time to consider this because he's shoved her back against the door to feast on recently uncovered flesh. Tangling her fingers in his curls, she pulls a little to try to get some relief from the heated suction of his lips; he ignores her, just holding her with one hand and sliding his other hand down to grip her with surprising possessiveness.

She feels one of his fingers tracing the lace pattern and refuses to make a sound; it will only go to his head.

Drawing back, he looks at her. "How attached are you to these?"

"How attached am I to …" she catches his meaning and shakes her head quickly. "Derek, don't you dare – "

He's already torn them off her, the lace ripping loudly, and she curses, pushing him hard. "I like those!"

"Liked," he corrects her, not looking sorry at all, and she's reminded that she's naked – except for her shoes and her necklace, damn but he's good, and he fists the heavy chain to pull her toward him. Not to be outdone, she shoves his lab coat off his shoulders; she's been divesting him of his scrubs since longer than they've been married –

were married, were married, it's past perfect tense now, it's complete, it's done

…so she's fast, and accurate, and he kicks his scrub bottoms across the floor and presses her up against the door again. She entertains a few unwelcome visions of getting shoved right through the door, naked, which would make for a memorable visit to Seattle, anyway.

"Did you even lock the door?"

Doubt crosses his face – nice to know he can have the occasional doubt – but then he looks relieved when he checks.

"It's locked."

"Can you just – " She pushes at him, indicating she wants to move away from the door, and sees his conflicted expression: he knows she's right, but doesn't want to give in.

Just some healthy husband and wife power struggles.

Ex-husband and ex-wife, I mean.

Ex-life.

He obliges, though, half dragging and half carrying her away from the door to shove her up against the sturdier wall and then looks down at her, eyes hooded with lust.

"Ready?"

She raises her eyebrows at him, which takes some focus based on what he's currently doing with his hands. "What if I say no?"

"Then I won't believe you."

She shrugs.

"Get ready then," he warns her, and she smirks at him now, enjoying it, and then her smirk becomes a gasp when he hikes her leg up and slams into her.

With no time for her to adjust, he drags them both into a rhythm that will feel exhausting soon. It doesn't hurt, exactly, but it's overwhelming. Overpowering. She pushes him away, not ready to give up the fight; he lets her and she slides down on shaking legs, missing the feeling of him inside her – the one way of accommodating him that usually – usually – didn't end in regrets. He follows her across the room; the part of him that isn't hers anymore but that she still remembers in fine detail is pointed at her like an accusation.

She backs away slowly, torn between not wanting to give ground and not wanting to turn her head in case he's planning – something, and she knows she's acting like prey and based on his predatory grin he's enjoying it; based on the ringing pulse in her ears, so's she. Damn it.

The bed hits the back of her legs and then he's on top of her, his weight so familiar and insistent that she sighs before she can stop herself.

"Next time I want my test results, get my test results," he growls into her ear as he pins both arms over her head.

"I'm not your intern. Get them yourself," she snaps back.

He switches his position so he's gripping both her wrists in one of his hands, the other sliding between their bodies; she has to swallow a gasp, hard, but she can tell by his smug expression that he didn't miss it.

"Want to reconsider that?" His tone is calm.

"No," she snaps. "Stop being an arrogant ass and try to consider for just one second that there are other – oh!" He's pushed two fingers inside her without warning and they're twisting in a a way that straddles the border between pleasure and pain; certainly in a way that interferes with rational thought.

"Stop."

"You want me to?" His hand stills its movements. "We can stop right now and you can go do your damn job instead of complaining about it."

"My job?" She stares at him, offended. He's not moving anymore but his fingers are still inside her, pinning her. "My job. This is your patient, as you keep repeating, and this is your hospital, which means I'm doing you a freaking favor and you're too arrogant to realize you should be thanking me."

He twists his fingers without warning and she gasps. "Thank you," he says, sounding almost sincere, dipping his head to take delicate flesh between his teeth and her body snaps to attention under his mouth.

"So," he continues, sounding calm again, but pushing down on the arms he's pinned over her head as if to remind her she's trapped. "Are we stopping or not?"

He parts his legs over her as she considers the question, clearly enjoying the way she's flattened under him; slipping his hand out of wanting flesh, he slides it instead up her rib cage, palming a breast roughly and then tugging insistently on pebbled flesh when she protests.

"Well?"

She doesn't answer. With both her hands trapped she has limited options – or rather a less creative woman might have limited options, but she braces herself against the mattress and traps him with her thighs in return, arching up to him in a way that puts pressure exactly where she wants it and rolling her hips in a way she knows will drive him –

"Enough!" With a cry of frustration he releases her hands and uses his to muscle her hips down, separating their bodies. She grins at him and he glares down at her.

"My patient," he says insistently.

"Tell yourself that when I'm on a plane back to California," she retorts.

"Stop fighting me," he snaps.

"Never."

The word slips out automatically; he grabs her in response and flips them both so she's on her belly. Covering her body with his, this time pulling her arms behind her back to pin them, he eases his weight off her and urges her onto her knees. Releasing her wrists only to grab a handful of her newly short hair, sweat-dampened and mussed already, he orders her not to move her hands.

Without the friction she needs, she's distracted, thighs pressing against each other.

He tugs on her hair, which feels irritatingly good, the nerve endings of her scalp alive. Why does he have to be so good at this?

"Do you hear me?"

"Fine," she snaps, "just do it already."

She feels his frustration next to and behind her as he knots his fingers even more tightly in her hair. "Stop. Telling. Me. What. To. Do," and with that one hand pushes her head toward the pillow, the other guiding her flesh open before he slams his way back into her. She gasps, the momentum pushing her forward. He drags her back up and thrust into her again, groaning. He's deep enough inside her that she's going to feel this tomorrow – hell, she's feeling it now. But even though she should hate him and she should definitely push him away and there's nothing restraining her hands except for his words, she's keeping her wrists locked behind her back of their own accord while he braces himself with a hand on the bed next to her head and drives deeply into her, again and again, and she feels his frustration fill her body.

"I'm tired of doing what you want," he snaps.

She turns her head the very little she can manage in this position. "When did you ever do what I wanted?"

"Oh, that's right," and she can tell by his tone he's glaring at her. He pulls all the way out and pushes back in with enough force to flatten her onto the bed and she can't protest because she doesn't want him to stop. Damn it. He pulls out, grabbing her hips and pulling her back with him.

"Would you stay up,"he snaps at her, punctuating his point with a hard slap.

"Would you stop rutting like a pit bull in heat," she snaps back, crying out when he slaps her again, twice this time. He pauses to admire the red marks he's left on her flesh.

"I'm done taking orders from you," he tells her simply.

"Likewise," she snaps.

"Really?" He sounds amused. "Then why are your hands still behind your back?" And he laughs at her, leaning over to nip the skin at her arms.

Damn it. Again. She doesn't have a good answer for that.

"Admit it, Addison. You love this."

She doesn't say anything.

Actually … no need to admit it. It's perfectly clear as he hands move underneath her, fingers buried in her obvious need. Her flesh is swollen, aching for release, but he avoids anything that could bring her satisfaction, just pulling her back up to her knees again.

"Your stamina has decreased," he says coolly as if he's evaluating her physical fitness and she glares as much as she can with her face shoved into a pillow and still hoping he'll actually finish the job.

"Can I move my hands?"

"No," he says immediately, "but I do like that you asked." He lowers his lips to the nape of her neck. "If you're going to be that good … you might get a reward after all."

"Don't do me any favors," she snaps, hissing when his hand falls again on already-reddened flesh.

"So close," he taunts her, "but you just can't help trying to tell me what to do, can you?" His fingers trace the handprints he left behind, pressing the pad of his thumb into the flesh to enjoy watching it turn white, and then pink again. One hand disappears between her beckoning thighs; she groans and he does too, warm velvet sucking him in and he can't move or think for a moment.

Her hands are still clasped behind her back, though, and he can't help smiling at that, not a little impressed either: she was always bossy as hell but god, she was always hot like this, too, especially when she surprised him. He's admiring the view when he sees the faint trembling in her biceps.

"Arms tired?"

She nods against the flat pillow. He rests his palms on her upper arms and massages them gently, dragging his lips along the inside of her forearms where the skin is eggshell white and silky soft. He can hear her breathing huskily, and knows she's dying for him to touch her but won't ask. He releases her then and flips her over, enjoying the feeling of how light she is in his arms, how easy it is to turn her around, to move her from one place to the next, to overpower her.

When she looks up at him her lids are heavy with need; she's different from the last time he had her on her back, when she was shoving at him and trying to take control; now she's lying quietly underneath him, arms resting placidly on either side of her head. He frowns a little, missing the fight. He presses the heel of his hand against the source of her heat, grinding it against the flesh that's begging for his touch, and she whimpers obligingly, hips rising automatically to increase the pressure.

He laughs. "Shameless," he scolds her.

"Please." She writhes underneath him. "Derek…"

Wordlessly, he grasps a thigh in either hand and pushes her legs up, so far back she's practically curled, and pushes into her without warning. She cries out and he waits a second or two; they've been going for a while and she'll feel it but it's nothing compared to what they've done in the past, what they could still to today if she keeps fighting him, refuses to admit she's wrong…

We didn't bother to fight anymore, that's what she said once. Which is too bad. Because their fights … their fights were memorable.

"You're not always right," he tells her now, because in his experience it's a surefire way to get her to fight back.

"I am right," she insists immediately, "you just don't like losing."

He laughs at her, enjoying the irritation in her expression. "Losing? Really? Because you don't exactly seem to be in the winner's position." He's picking up the pace as his breaths start to stagger and she's meeting him in the middle, hips rising when his slam into hers, and then he sees her hand drift to where their bodies are joined and stops, stilling all movement inside her.

"What do you think you're doing?"

She looks up at him under her lashes. "Nothing."

"Better be nothing." He cups a hand over the flesh in question. "No one touches this but me."

She raises an eyebrow. "We're divorced," she reminds him.

"I don't care," he snaps.

She blinks at the possessive tone in his voice. "Well, that's just too bad Derek, because you signed away any claim to – oh!" She cries out as he changes the angle of his hips to thrust in that specific way makes her feel like there are fireworks going off behind her eyes. It's one of those things he knows to do, know about her, that she's never been able to get anywhere else, because … however it sounds, there's just no substitute for so many years of enthusiastic, energetic practice on each other.

There's pressure building behind her eyes and her muscles are clenching; he smiles down at her, obviously recognizing what he's doing and looking pleased with himself.

"You were saying?"

She ignores him, half expecting him to stop until she answers, but he doesn't. Looking her right in the eyes, he lowers his hand and, with just his thumb between them, in the series of flicks and steady pressure that became second nature at least ten years ago, he brings her to a staggering, pleading, finish.

He doesn't move, enjoying her convulsing around him, maintaining control with nothing more than practice and determination – though it's hard, especially as she looks up at him with glazed eyes and a slow, spreading smile.

"Showoff," she pants.

He laughs at her. "Just because some of us have stamina."

"I'm not going to be able to stand after this," she complains.

"You'd better be able to stand. I may need you in the OR."

"Derek…"

"I need you," he says again. "I need you to stay." He moves inside her more slowly without as much urgency now, taking his time, letting the sensations surround him. Her hands cupping his clenching muscles assure him that she's agreeing to stay, and then he pauses.

"You're on birth control, right?"

The most effective form: she's barren. "Yeah," she pants, hoping he doesn't ask her which kind; that would be an awkward conversation.

She just smiles up at him and lifts her hips to meet his, ignoring her exhaustion and trembling muscles to clench him with everything she has and bring him over the edge; when he barks out her name – half anger, half … is it regret? – she decides it was worth it.

He collapses on top of her and she runs her fingers through his sweat-dampened curls. "So much for stamina," she purrs.

"Shut up," he says, nipping weakly at the flesh of her neck without moving his exhausted head.

"You shut up," she responds, and then they're both quiet.

…

He glances either way down the hall before ducking out of the room, running his hands through his hair again even though he's pretty sure each time makes it wilder. He's halfway down the hall, pretending to scan the board; he knows the routine well. As for Addison, she waits the requisite sixty seconds – they calculated this a long time ago – and then he hears the clack clack of her heels as she reaches his side.

Checking for onlookers first, she straightens his lab coat just slightly. He nods at her jacket, which she tugs quickly into perfect place on her hips, then stands up to her full height. Footsteps are approaching. They walk as casually as they can until they're right where they started, on the catwalk.

Derek takes a step back from her and regards her coolly.

"So, Addison … you were saying?"

"I was saying," she says with as much dignity as she can muster when her insides feel like they're on fire and her thighs are jelly propped up on high heels, "that if you want your damn test results so badly, you can go check on them your damn self."

He stares at her. "Fine," he snaps, and victory surges through her.

She stalks off on shaking legs, knowing he's watching her. Take that, Seattle.

…

"Did you get the test results?"

"Your guy got them, actually," Alex tells Meredith, both standing a few feet away from where Addison and Derek are reviewing a folder of lab results, heads bent in the same direction over the desk. She's still wearing that prissy skirt suit thing and impossibly high heels even though Alex is well aware she's been up all night.

Meredith looks doubtful. "My guy got your guy's test results?"

Alex nods. "It's your guy's patient," he reminds her.

Meredith raises an eyebrow. "I'm glad to see your guy acknowledging that."

Alex and Meredith watch the former spouses for a moment as they review a folder of lab results, heads bent in the same direction; Addison points to something on the paper with one polished fingernail and they see Derek nod in response.

"You know … your guy actually seems to be in a better mood," Alex observes.

"Your guy does too," Meredith responds.

Shrugging, they stroll away in opposite directions. They have work to do.

Self-indulgent and a little filthy? Wait, how did you know my middle names?

If you enjoyed, please let me know. So here's the deal - I usually don't write Addek when one of them is cheating on someone else, but the crossover was such a strange little universe that it seems separate to me. Plus, this is pure fantasy.

So I can't be the only one who thinks a little angry Addek sex could heal the world ... or at least the show, right? And I promise I will update all my outstanding stories soon. If there's one in particular you're jonesing for, tell me! And ... please review, because it may be self-indulgent, but this story is still for you! xoxo