Hi, this is my first Grey's Anatomy fic, so please be kind, but let me know what you think. :) I'm not really sure what kind of a shipper I am yet… I just love Addison. There's some Maddison and Addek, since I'm doing a backstory. I decided that there must be more to the story of Addison/Mark sleeping together than we know, so I decided to write it, considering Mark's POV… So this is sort of his reflection, though I wrote it in third person. There are some breaks in his line of thought, but I think that you'll be able to understand the flow. This takes place in the middle of Six Days, Part 2.

For the sake of a timeline… I'm going to assume that they all went to the same medical school at age 22, that they graduated med school at 26, that Addison and Derek got married right out of med school… And that they are now around 37ish.

There are some mildly naughty bits, so if you're not old enough to read that, don't… I don't want to be responsible for the corruption of the world's youth.

Oh, and I don't own any of these characters or this show, and if I did, I'd be sunning in the Bahamas instead of suffering through grad school in the never ending snow.


"I did want a baby… I just didn't want one with you."

Mark sat in his office, staring into his coffee, Addison's words reverberating in his head. They stung… But they were true.

Things could have been different.

After all, he saw her first.

Beautiful Addison at 22. She was sauntered into his life wearing stiletto heels, dressy black pants, and a blue silk dress shirt, with her flaming hair neatly combed to frame her face. She had looked much more like she was scheduled to appear in a runway show than her first day of medical school.

They were paired together as lab partners. After class, as she was gathering her books, Mark decided to make a move.

"My roommate, Derek, and I are having a party this Saturday. 276 Willow. Starts at 9. You interested?" Mark asked with a coy smile.

"In you or the party?" Addison replied with a wink.

His face broke into a grin. "Either."

"I don't know. Maybe I'll see you there."

With that, she left.

She had shown up at the party. Fashionably late, but looking even more amazing than the first day of class. He saw the eyes of his best friend immediately flick over the redhead with interest, and a smile warmed his face. Mark hadn't seen Derek respond to anyone that way since Haley, his high school sweetheart.

Haley had followed Derek to college, and everyone was certain that they would be married one day. A drunk driving accident during Christmas vacation changed everything, leaving Haley with a traumatic brain injury.

For days, she lay in the hospital bed in a coma. Mark had been there those days, had stood by Derek's side, and watched his best friend break down into tears when he had to say goodbye.

After Haley died, Derek threw himself completely into his schoolwork, unwilling to go out on dates or socialize much beyond what was required of him in class. He was determined to become a neurologist. It was the only way he thought he could give back to Haley, trying to save other people from the pain he had felt when he lost her.

Mark watched as Derek handed Addison a beer, and began chatting with her eagerly. Mark let out a sigh and flopped onto the couch. It had been a long time since he had seen Derek happy like that with a woman, and he wasn't going to fight him for her. They were like brothers. The crush would surely pass, Mark thought.

But it never did.

As Addison and Derek grew closer and she spent more time at their apartment, her belongings began to accumulate there. A heart-shaped perfume bottle, filled with a violet scented fragrance. A pink razor in the bathtub. Claw shaped hair clips. Mark couldn't set foot anywhere without being reminded of her, and it drove him insane.

Eventually, Derek moved out of their apartment and in with Addison. Meanwhile, Mark set out on a mission of his own. It was fairly simple. His coping mechanism was women. Many, many women. They became an addiction. Nurses, fellow doctors, the occasional patient... Hell, even Derek's sister. The time spent rolling around in bed was meant to keep him from feeling so empty inside, but each morning that he crawled out of a strange woman's bed, he felt more alone.

While he was jumping from bed to bed, Addison and Derek grew closer. After three years of dating, Derek decided to pop the question. Lucky Mark had gotten to go with him to help pick out the engagement ring.

Addison loved snow. She loved stepping on it, sinking down into it with a satisfying crunch. Derek knew this. He had packed the black velvet box that held her delicate diamond engagement ring in a snowball and tossed it at her. Even Mark had to give that one to him; it was clever. When the snowball broke apart, the box fell to the ground, and so did Addison's jaw. She'd squealed and tackled Derek in the snow, saying yes repeatedly and showering his face with kisses.

Mark dutifully stood next to Derek at the altar on their wedding day. The ceremony was held in a huge cathedral, with tall, colorful stained glass windows and calla lilies stuffed in every corner. Addison's father was a corporate attorney for a technology firm, and nothing was too good for his baby girl. The wedding was amazing. Mark tried to ignore the stabbing pain in his chest when Addison walked down the aisle, her eyes never leaving Derek's. Tried not to notice how amazing she looked in the strapless ivory gown, which was hand beaded from the bodice to the train in rum pink pearls. Tried not to think about how if he would have asked her on a date instead of to the party, she might have fallen for him first, and he and Derek could have been standing in each other's places.

Then, there was that night that he did stand in Derek's place. He hadn't planned for them to have sex that night. Hadn't planned to join the "Dirty Mistresses' Club."

Addison had the flu. Derek, as usual, was too busy to care for her. All three of them were surgeons, and busy with work, but only Derek threw himself into his work so hard that he literally had no time left for anything else but a bit of sleeping and eating.

As Mark was leaving work that night, Derek had caught his arm.

"Hey, can you do me a favor?" Derek asked. Mark looked at him questioningly.

"Can you take Addison some dinner? She's sick and I have some charts I should get to…" Derek fished a 50 out of his scrubs.

Mark waved his hand at the money. "Forget the money. Sure thing." By that time, he was used to looking after Addison for Derek.

Chinese food was always a winner with Addison. He'd spent enough time with the couple to know exactly what she liked. Vegetable lo mein, wonton soup, an eggroll. Had to be duck sauce, not sweet and sour. And if she didn't get a fortune cookie, there would be hell to pay.

Mark bought everything he thought she would like at a great Chinese place near the hospital, and headed to the brownstone in his Jaguar. To most people, she would have looked horrible. Her skin was pale, her red tendrils snarled on her head like a bird's nest, and she was in a bathrobe and slippers. He still thought she was beautiful.

"He sent you…" Addison said sadly, stepping aside so Mark could walk in.

"I'm sorry." Mark set the food down on the counter. "I know I'm not Derek, but… Would you like some company?"

"Sure. Thank you for the food. I'm actually pretty hungry." Addison said.

She went for the fortune cookies first. She always did. The whole, "life's short, so eat dessert first" mentality.

She snapped the cookie in two and read aloud, "The one who loves you is closer than you think."

"Eh. Yeah, right." She crunched down on the cookie and tossed the fortune aside, and continued to dig through the bags.

"Ooo, lo mein!" Addison perked up a bit.

Mark was happy to see her smile. Addison claimed the box and a pair of chopsticks, and padded back into the living room, where a movie was playing on the plasma television.

"I've been watching Breakfast at Tiffany's." Addison said sheepishly.

Mark joined her on the couch with his General Tso's Chicken. For a while, they watched the movie together in silence as they ate.

During a particularly romantic scene between Holly and Paul, Addison suddenly dropped her chopsticks into her noodles. "Do you think he still loves me?" she asked, looking directly into his eyes, her own filled with tears.

"He'd be crazy not to." Mark said softly.

He wanted to give her more comforting words. He wanted to tell her that her marriage wasn't falling apart. But Derek had been acting strangely lately, and he couldn't promise her anything. Instead, he brushed a fallen tear from her cheek.

It was a mistake. Touching her was a mistake.

He hadn't meant to kiss her. Hadn't mean to slowly lower his lips onto hers and pull her against his body. To his surprise, she responded, even took charge, gently pressing her tongue between his lips to stroke his softly.

He didn't walk in there with Chinese food intending to follow her upstairs to the bedroom, or slide off her bathrobe, or toss it to the side.

"Make love to me, Mark," Addison pleaded.

She looked so hurt, so sad. He'd seen her look that way more times than he would have cared to in the past couple of years.

"Addison…"

"Mark, I know what I'm doing. I'm a grown woman. Please." Addison said, lying down on the bed.

"I shouldn't be doing this… I shouldn't be having sex with my best friend's wife… I…"

Mark was cut off when Addison pulled him on top of her, pressing her lips against his. He kissed down her jaw line, her neck, her collarbone, before burying his face between her perfectly shaped breasts. He'd seen a lot of breasts in his job and his personal life, but none matched hers. Even his work couldn't beat nature's.

He inhaled the smell of violets that had driven him crazy for so long. She hadn't changed perfume in 15 years. Her body was hot, feverish against his, but he didn't care. Let the germs invade his body. Let him be bedridden with influenza for 2 weeks. It'd be worth it.

Mark normally liked it rough. But not with Addison. It was different with her. He was tender, gentle with his touch. Every curve of her skin he caressed. Every kiss he gave her. Gentle. It could be the first, last, and only time he would hold her that way. He wanted to savor it. He couldn't tell her he'd loved her all of those years. Not then. He had to settle for showing her with his body.

"I… uh… I don't think that's what Derek meant when he asked you to check in on me." Addison said quietly after they finished, moving her head to rest comfortably on Mark's chest.

"No, I'd say not…" Mark said, tangling his fingers in her long locks and kissing her burning forehead.

They didn't hear Derek come in. They did look up just in time to see the flash of anger in his eyes, and the slamming of the door behind him.

That was the night they had created their child. On the first try. She and Derek hadn't been intimate with each other in months, and she had even gone off of her birth control. She, of all people, should have known better.

Despite himself, his thoughts were back to the child again… Why had he slept with the nurse? He'd finally had what he wanted for fifteen years, and he'd blown it, getting caught by Addison with his pants down… Literally, in an on-call room. It could have been perfect, if he could have resisted Charlene's advances. She'd come onto him, but why couldn't he say no?

The next few days happened too fast. Addison kicked him out, had the abortion, and hopped a flight to Seattle.

Derek took advantage of her for years, and Mark had hated him for that. Then he'd gone and done the same thing.

She deserved better than either of them.

But that didn't mean he was going to stop trying…