The original and ultimate FMS prompt from Fatema's: present-day Derek, Mark and Addison stuck sharing a cab from a conference in New York. Derek's an angry drunk, Addison's a friendly drunk, Mark's not that drunk at all - and wildly inappropriate things ensue. Written during the summer hiatus, and rated M for a reason.

Backseat Driving

"I told you to stay on Park. It would have been much faster. Why are you -"

"Fifth is better," the driver snaps from the front seat.

"No, it's not!" Addison protests, her words slurring only a little considering how much alcohol she'd consumed at the post-lecture cocktail party. Then again, it was certainly less than she was going to need to get through an awkwardly slow cab ride with some of the worst mistakes of her past sitting on either side of her. "Here, make the left up -" she breaks off, feeling eyes on her. "What?"

"Nothing," Mark says mildly. He's holding his liquor fairly well for someone who couldn't avoid presenting at a conference with both Addison and Derek - who, at the moment, is staring out the window, a Heathcliff-style brooding drunk as usual. Outside, it's a hot and breath-stealing New York August, Mark and Derek in half-rolled shirtsleeves, Addison in the closest thing to a sundress she thought she could get away with at the notoriously stuffy conference. Inside the cab, the icy chill from the air conditioning rivals the one from their shared past.

"What?" she demands again, poking at Mark and trying not to notice the warmth and strength of the hand that captures hers. It's dark in the backseat of the taxi and they're lined up in the familiar pattern they perfected decades ago in New York: Derek behind the driver - he always gets in first. Addison, the smallest, in the middle. Mark, who holds his liquor best, sliding in last only when he knows both his friends - well, his old friends, anyway - are safely ensconced.

"It's just interesting to see some things don't change," Mark comments drily. "You're still an insufferable back seat driver."

"I am not! " She yanks her hand away now. "I just know where I need to go, and -"

"-and don't trust anyone else to take you there."

"Just because you were never a good driver-"

"I'm a great driver."

She rolls her eyes at Mark's saucy grin. Of course he would make this sexual. Mark could make anything sexual - despite the fact that he's had the least to drink of the three of them. (Though admittedly, she and Derek set a pretty high bar.) She stares directly back at him now: two can play this game. "Well," she says deliberately, running her tongue just slightly over her lips, "sometimes you may think you're driving in the right direction, but the road you're going down isn't the right road, and you just keep driving over the same streets again and again and again and again and-"

"I get the idea," he cuts her off. "You saying this one-" he motions with his chin at Derek - "Is a better driver than I am?"

"I didn't say that. Derek-" he's studiously ignoring her, but she continues anyway - "Derek would pick a route and if it didn't get to ... his destination, he'd just call off the trip."

Mark laughs triumphantly. "Sounds like I'm the better driver. Just like I thought."

Derek, who has apparently been listening, shoots an angry glare at both of them. "Are you the car in this metaphor, Addison? Do you really want to go there?"

"I'm a Ferrari," she slurs, giggling. "Or something else red...and fast."

"More like a Pinto," he snaps, scotch on his breath.

She sinks lower into her seat, hurt.

"Don't be a dick," Mark shoves at Derek with his free hand.

Derek shoves back. "You have a lot of nerve defending her after what the two of you - a lot of nerve."

"Maybe if you'd defended her once in a while, none of this would have happened."

"Drop it, Mark." His voice is icy; he's always tended toward being an angry drunk. He checks his watch, annoyed. "We've been sitting here for - this traffic is ridiculous," he snaps over the blaring of a horn behind them.

Addison, ever the friendly drunk, tries to loop an arm around his neck and he bats it down. "Cut it out."

Mark reaches across Addison to shove Derek again, harder. "What is your problem?"

"My problem is that I'm trapped in traffic in the backseat of a cab with my adulterous ex-wife and the man who destroyed my marriage with no hope of getting any sleep tonight and - " his voice breaks off, something else behind the anger.

Mark and Addison turn identical expressions of curiosity to him and he groans. "-and I think my second marriage is over too."

"What?" Curiosity turns to concern.

"Meredith left me. Or I left her. I don't know. We left each other."

Silence, then: "Lexie's dating a resident and she told me to leave her alone."

Addison works a hand over to Mark's side to give him a comforting pat on the knee, then an elbow in the ribs when he tries to move her hand higher.

"Sam said he'd 'try' to love me, so I told him to take a hike," she admits.

All three slump back against the cracked leather seat.

"What happened to us?" Mark asks.

"Maybe we're getting old," Addison offers.

"No, we're supposed to be in our prime," Derek counters weakly.

"She'sin her prime." Mark jerks his thumb toward Addison. "We peaked in our teens, man. Remember?"

Derek nods sadly. "I do remember."

"Oh, please." Addison rolls her eyes. "We were married for eleven years, in case it's slipped your mind. I've seen your childhood room. I've talked to your sisters. When you were a teenager the only thing that peaked was your risk of carpal tunnel syndrome from-"

"Either way, the point is the same," Derek interrupts hurriedly. His eyes are faraway, misty even in the dim light, and Addison could never stand his sadness for long.

"I'm sorry," she says honestly, patting his thigh. He doesn't push her away this time.

"I"m sorry too, man." Mark reaches for Derek, doesn't quite make it, and lets his hand curl around Addison's leg instead.

"Sorry for what?" Derek scowls.

"Everything," Mark says simply.

"Me too, for everything." Addison runs her fingers lightly along the warm plane of Derek's leg and then he does snatch her hand off.

"What are you doing?"

She shrugs. "Saying I'm sorry."

"Sorry can't fix everything. It's in the past anyway." He turns his head again to look out the window again. Addison sighs, replaces her hand and trails it higher along the crisp fabric of his suit - perfectly tailored, probably one she bought for him - it's not like they haven't done this in a cab before. There was the time in medical school when -

"Addison, what the hell?"

"Sorry doesn't fix everything, fine," she says firmly, perhaps more sober than she thought. "So let me fix it." And then she giggles, betraying her (lack of) sobriety and Derek relents. He's always loved the way she laughs, though he's not sure he ever told her that, and the way she -

"Jesus, Addison, we're in a cab."

"I know where we are."

"Do you know that I'm still sitting right here?" Mark interjects.

"How can I not know that when your hand is on my ass?" she hisses back.

"Your ass is on my hand!" he protests, and she realizes he's sort of right. "Maybe if you sat down in your seat like an adult and not a sex-starved teenager-"

"I'm sorry, Mark, did you just call me sex-starved? No, wait, did you just imply that Ican't control myself?"

"Are you saying you can?"

"Hello?" Derek's tone is annoyed. "Did the two of you forget I'm here? I know that's happened before."

"I thought that was in the past," Addison snaps.

"I think I have perpetual right to remind the two of you that I walked in on-" Addison silences him with her lips. He tastes somehow exactly the same and completely different from how she remembers. He freezes, then cups the side of her head and sweeps his tongue along hers the way he used to.

"And now you two are forgetting about me again." Mark slips a hand under the half-risen skirt of Addison's dress. "Seems like the only person no one is forgetting about is you."

"I'm in the middle," she shrugs.

Then Derek's hand is on her other leg, sliding confidently up her thigh while Mark's fingers climb higher and she jerks at the contact, her head banging back against the seat. The driver gives her a curious look in the rearview mirror and she shoves at both of their hands, blushing furiously. "Who are the sex-starved teenagers now?"

"We're drunk," Derek says dismissively. "It doesn't mean anything."

Mark leans over, pressing his warm mouth to the cool skin just above the neckline of her dress. She arches her back automatically, pushing her flesh higher against his lips; Derek swallows her gasp with another kiss.

"Enough," Addison wriggles free, straightening her dress.

"You're not enjoying this?" Mark asks, breath tickling her ear.

"No," she says primly, then curses herself for cursing when Mark's talented fingers slide back under her skirt, brushing all too briefly against her center.

"The state of this tells me otherwise," he gloats, cupping her lightly through the damp ivory silk of her panties and smirking when she bucks shamelessly into his hand.

She squeezes her eyes closed, shuddering, and when she opens them Derek is studying her calmly, almost clinically, as she writhes as discreetly as possible under Mark's hand. Then one finger slides inside the silk barrier and she has to bury her head in Derek's shoulder to stifle her moan, biting down hard when Mark crooks his finger exactly the way he knows drives her crazy.

Derek strokes her hair soothingly. "I thought you weren't enjoying this?"

"I- oh," she groans as Mark withdraws his finger, brushing his knuckles firmly against the heated flesh.

"Or do you only enjoy it when you're calling the shots?" Mark asks innocently, flicking his finger against her again, making her squawk into the damp fabric of Derek's shirt.

"A backseat driver to the end," Derek observes. He runs his hand softly down her jaw, her neck, just barely brushing the heaving flesh at the top of her dress. She strains against his hand, trying to get him to touch the parts of her crying out for his attention, but he ignores her.

"Something must be wrong. Traffic not supposed to be like this." The driver's voice from the front of the cab startles all three of them, Addison jumping in her seat.

"Shh," Mark palms soothing circles on her thigh as Derek presses his fingers against her mouth.

"We sit here for ten minutes already. Is not right."

"Maybe there's an accident," Derek calls out when it becomes clear that the driver is waiting for an answer.

"We have not moved. Something is wrong. I will get out and look."

"Out of the cab?" Addison squeaks.

"Could be big problem. I go look." The driver turns off the motor. "Three minutes, I be back."

He slams the door behind him and this time all three of them jump.

Then Mark smiles wickedly above her. "Three minutes," he murmurs.

"What can we do in three minutes?" Derek asks with mock curiosity, taking advantage of their newly won privacy to cup a breast through the thin fabric of Addison's dress.

"What are you -" Addison gasps as Derek's thumb toys with her nipple.

"With this one?" Mark nods affectionately toward Addison. "Sky's the limit in three minutes, man."

Derek nods sagely.

"What are you-" Addison tries again, but the words die in her throat as Mark and Derek move in perfect harmony, Derek lifting the upper half of her body into his lap while Mark slides off the seat, crouching on the floor of the cab.

"Three minutes," Mark says. "Piece of cake." His hands slide up her thighs and she cries out, not bothering to muffle it now as Mark flips the thankfully a-line skirt of her dress up and away. He cups her ass, lifting her closer to his face and, with a saucy grin she knows all too well, rips off the silk barrier between his lips and her pleasure.

"Hey! Those were expensive," she protests.

"I'll buy you a new pair," he says, and dips his tongue into her, making her shriek.

"Forget it," she pants. "We're even."

Mark winks at her, then disappears between her thighs again. It's Markand it's so good, her cheeks are tingling with heat, her lashes fluttering; above her, Derek palms her breasts, squeezing lightly as she flexes and arcs away from the intense sensations. Mark presses a soft kiss inches from where she is desperate to feel him and she thrusts her hips higher.

"A little to the left," she whispers, undulating with the motion of his lips. "Can you just-"

"Hey, here's a thought," Mark growls against her thigh, stubble raising gooseflesh and the pitch of her moans all at once. "How about you cut out the backseat driving once and for all?"

She's too lost in sensation to respond, one hand locked in Mark's hair, the other dancing at his jawline, trying to direct him exactly where he needs to-

"Oh!' she cries out as strong fingers close around her wrists and pull them up and over her head. When her eyes flutter open she sees Mark, his face still inches from where she desperately wants it to return, exchanging a knowing glance with - she twists around and Derek is grinning, both of Addison's captured wrists encircled in one of his hands. With the other he traces a lazy circle around one breast. She twists with pleasurable agony, neither set of hands or mouths exactly where she wants them.

She's pressed closely enough to Derek to feel exactly how much he's enjoying her frustration; it only excites her further as she writhes against first Mark's lips, then Derek's questing hand. He tugs her captured wrists higher, stretching her arms until she's forced to arch her back, pushing her breasts toward the ceiling and wrenching a moan from at least one of the men in the cab. Derek leans forward, tugging one nipple into his mouth through the thin fabric of her dress, nipping with just enough force to make her yelp while the motion of Mark's tongue at her center turns the yelp into a groan. Her hips buck off the seat until they too are captured and pinned to the cracked leather.

With nowhere to move and no ability to direct either of the men's hands and mouths, she surrenders to the overwhelming sensations. They work expertly in tandem - they've always been a good team - bringing her right to the brink and then withdrawing, keeping her on the edge of explosion, the most exquisite of tortures. She's slicked over with sweat, too slippery for purchase. Her heels - of course, Mark would have wanted her to leave them on - poke the doorframe as she slides against his talented mouth. He wields his tongue like a weapon, just as she remembers, and then she cries out, unable to lift her hips, when she feels the rough pad of a finger skate over sensitive flesh.

She opens her eyes just for a second, too many sensations at once, to see Derek's hand and Mark's lips and "You wanted both of us," Derek whispers against her ear, nipping at the sensitive flesh behind it. "Now you have us." A rough swipe of his thumb and firm pressure from the curl of Mark's tongue send her over the edge, her scream echoing in the enclosed space. Derek withdraws his fingers, presses them to her lips and she sucks them into her mouth obligingly, distractedly, as she tries to come down from her high. Mark rests his scratchy cheek against the inside of her thigh, blowing gentle puffs of cool air on her heated center as she convulses.

"Three minutes," Mark murmurs, teasing her for just a moment with his tongue - she jumps under his hands, aftershocks leaving her thighs trembling. "I told you-"

The front door opens with a groan and Addison jumps again, Mark quickly yanking her dress down her legs and helping her sit up.

"Accident is cleared," the driver says, apparently oblivious to the heaving breaths and awkward looks in the backseat. He turns the engine on. "Now will be no problem."

Addison gulps as the motor's vibrations head straight for her sensitive core.

On her right, Mark is swallowing hard, trying to train his eyes away from the flushed skin disappearing into Addison's bodice.

On her left, Derek is shifting in his seat, trying to catch his breath.

"We get to midtown ten minutes now. No problem."

"Uh...thanks. Yeah." Mark is breathing heavily, swiping the back of his hand across his mouth, the taste of her on his lips increasing the throbbing between his legs. "Just, uh-"

"Mark," Addison hisses, tugging on his sleeve. Her eyes are still half-closed, heavy lidded and huge. "The hotel ...we can... finish..."

It's the longest cab ride of his life.

Judging by the clock, the driver was right - it's barely ten minutes from the stall on Fifth Avenue to their midtown hotel. But inside it's the longest cab ride of Mark's life - and once, in a drunken stupor, he paid a driver to take him and his latest conquest all the way to Niagara Falls, where she threw up copiously off the side of the Maid of the Mist and he paid through the nose for dramamine in the overpriced gift shop. This time, his pants unbearably tight, flinching every time Addison's half-bare thigh brushes his, the ride truly feels endless.

He glances at his old friends, maybe his new friends - Addison is leaning her head back against the seat, mouth half open, breasts rising and falling unevenly with her staggered breaths. She arches an eyebrow at him and he turns his head quickly before he embarrasses himself. Addison always was a friendly drunk. Next to her, Derek is scowling at his folded hands, crossed conveniently in his lap. He still looks angry. Or maybe just horny - Mark reminds himself to ask Addison this at a more opportune moment - "shit, cut it out!" he pushes her hand away from his leg.

"Addison, can you please try to be-"

"Professional?" she asks, with the smirk that she knows perfectly well drives him crazy. Apparently she's fully recovered.

"Patient," he says. "A little patient. We're almost th-Addison!"

"Isn't turnabout fair play?"

"No," both men say in unison and Mark catches Derek's eye over Addison's head. They smile at each other, the first genuine smile he can remember their exchanging in a while. Lifelong friends, they don't need words to form a consensus: they agree silently that when they get to the hotel, they'll make her pay. Each of them breaks eye contact then, indulging in shared memory of the woman between them. They were wrong, maybe, to think she could drive them apart. They're not apart. She sits between them now, feigned innocence all over her swollen lips and pretty, flushed face. They're together - all of them - and they're going to enjoy this as much as she will.

But first it's Mark who pays - literally. When they finally arrive, he hands the driver a crisp hundred dollar bill, figuring it's the least he can do for one of the more memorable cab rides he's taken. "Show-off," Addison mutters, yelping when he pinches her. They tumble out of the taxi, Addison catching the hem of her dress on the ragged edge of the plexiglass barrier. It rips loudly and she curses.

"Stupid bulletproof glass," she mutters.

"Is not bulletproof," the driver says indignantly as Derek hefts himself out of the cab. Mark's mind is elsewhere, focused on the room waiting for them, king size bed, crisp white sheets, and -

"Wait, I thought all cabs had bulletproof glass now," he says as the door swings shut.

"No." The driver shakes his head. "We get a choice. For security. Bulletproof glass or video camera."

"Or - what?" Mark asks, leaning down to be heard through the half open window.

"Video camera." The driver points to the electronic eye staring accusingly at them from the ceiling of the cab. "Have a good night!" he calls, pulling away, the roar of the engine drowning out Addison's outraged scream.

Then they fall together into the king-sized bed in Mark's hotel room - it's on the lowest floor, so deemed the fastest - and together, they make Addison scream again. And again.

And again.

They ignore their wake up calls.

They miss their respective flights home.

They stumble shame-facedly from the hotel in the glaring midday sun, pour themselves into a town car to JFK.

"Do you have a preferred route?" the uniformed driver asks politely.

Addison rests a companionable hand on the knee of each man beside her. She shifts in her seat just enough to make it clear there's nothing under her beige linen dress, causing Mark to swallow hard and Derek to look quickly away and out the window. "Whichever way has the most traffic," Addison says slyly, settling in for a nice long ride.

I will always love these three. How about you?