Disclaimer: I don't own the characters! Or Al Pacino.

How it Started

It all started with Al Pacino.

Pacino was Mark's favorite actor (and idol, hence, all the leather jackets). He mentioned this at a dinner party one time, and it was one of those anecdotes that Derek made fun of, and Addison always remembered.

It was at a different party, and Derek wasn't there. This was the third charity event that Addison had been to in a month; she didn't even remember the cause. She did remember playing pool after, drinking a bit, and then telling Mark that she hadn't seen The Godfather.

He stared at her for almost a minute, and then threw back his drink and hers. She stared at him as he grabbed her hand, quickly escorting her to his SUV. He didn't say a word to her on the way to his apartment, but she wasn't scared.

She walked into his kitchen by herself, but he surprised her by picking her up and boosting her over his shoulder. She laughed when she saw his smile. In return, he pretended to drop her on the couch, but then caught her and gently placed her down.

She might have fallen asleep for a second because when she opened her eyes, Mark had turned on the DVD player and retrieved two beers from the kitchen. "It's so late," she said as the movie started.

"Nothing compared to what we endured in med school." Mark took a swig of beer and gestured to the television. "Watch the movie. It is imperative to your future well-being."

"I have to go home." She stood up and a blanket fell off of her. She realized that he intended her to stay. "Derek will be waiting," she explained.

"No, he won't." Mark didn't move. "He just called. You were sleeping."

Addison crossed her arms, the pitch of her voice raising until she mimicked the shrill tone of her mother, "Well, you should have woken me up. Didn't he want to talk to me?"

"Addison," he sighed with a slight groan of annoyance, "the conversation lasted less than a minute. He literally hung up after once sentence."

The tiniest whine escaped her mouth before she bit her lip, and turned around, looking for her coat. "I'm leaving," she said with no resolution at all.

He stood up. "No, you're not." He touched her hips, and then pulled away as if unsure about his actions. Hesitating, he rubbed the stubble of his chin, and then impulsively tugged at her dress, bringing her back on the couch.

She let him because he wanted to be with her, and her husband didn't. But he didn't push her, so she sat at the opposite edge of the couch. Three hours later, she was wide awake and snuggled into his side.

Mark was silent as the credits rolled down the screen. "So, what do you think?"

"You were right." She shook her head in defeat and smiled. "I can't believe I'd never seen that movie."

He pulled his arm from around her and stood up to turn off the DVD player. "I can't believe Derek never showed you that movie."

She pushed herself to sit up on the couch and twisted her hair in a bun, only to realize that she'd forgotten a hair tie. "Right. Hey, you don't have a hair tie, do you?"

He laughed, and directed to the bathroom. "I have scrunchies." He opened the bottom drawer under his sink, revealing a colorful disarray of fabric.

"Wow." She picked a pink tie-dye scrunchie up, and shot it towards him. He caught it at his chest, and threw it back at her. She knelt down to get a better look. "How did you get so many?" Her eyes widened in suspicion. "What do you do with these? Do you have a weird thing?"

"A weird thing?" He asked.

"You know…like a fetish." She crinkled her nose in disgust.

"No!" He shut the drawer with his leg. "If you were going to make fun of them, you shouldn't have asked for one."

She grabbed his leg and pulled it away. She felt his muscles flex under her fingertip, and smiled at this. All of a sudden, she forgot what his leg looked like under his pants. She'd seen it plenty of times before, but she couldn't remember, and she wanted to slide his sweats up to look at it.

She looked down and realized she was still wearing her dress. How ridiculous. She supposed it was less ridiculous than a drawer full of women's xcrunchines. "So, what are these?" She grabbed a handful of the scrunchies.

Mark sat on the edge of the bathtub, shrugging. "I had a lot of sex in the eighties."

"Seriously?" Addison dug deeper in the drawer, and her finger got caught around something with more lace and less elastic. She held up the string thong. "Not just a scrunchie collection?"

"That's not supposed to be in there." Mark grabbed it and threw it in the trashcan.

Addison raised her eyebrows in suspicion. "You keep hair ties, but not underwear?"

"Well, no one would ever want to use the underwear, but…" he grabbed one of the scrunchies and twisted her hair into a ponytail, "…you can use one of these."

Addison touched the back of her hair. "Oh…that's nice of you to think of your female guests." She smiled, kidding.

"So now you're a female guest?" He sat down on the cold bathroom floor with her. "You want the special treatment?"

"Mark." She looked away, withdrawing from him. She didn't want to be treated like one of his one night stands. She didn't want to lead him on, as if he'd ever want to be with her. But she had to remember that she was married. She wasn't allowed to flirt, regardless of how undesirable she appeared.

"I meant pancakes in the morning, Addison." He slammed the scrunchie drawer shut, and the sound of wood on wood contact vibrated loudly in the tiny bathroom. Addison jumped back, hitting her head against the wall.

"Ow," she reached up and tugged on her ponytail.

"Sorry." Mark drew his knees up and crossed them in front of him. He leaned back against the shower curtain, staring upward.

She whined, and frowned, her forehead crinkling. She could practically hear him warning her about wrinkles, so she relaxed her face and settled for staring into space.

They waited for almost a minute. He realized nothing would move forward until one of them stopped being stubborn. "Okay. Let's not do this."

"Then act normal." She was glad that he spoke first and that hoped he still wanted her there. "Don't pretend to be a hot-shot womanizer. I'm not one of those girls you meet in bars."

He watched her fingers trace the cracks in the tile and then looked up at her. His expression became lighter, almost smiling, "You see right through me."

She grinned and rose up onto her knees to crawl closer to him. She liked that she knew her husband's best friend so well. She hadn't been able to connect to someone so closely for a while. "Yeah."

She wasn't so coordinated, walking on her knees, and she fell over. When she straightened herself up, she saw she was holding his hand, but she didn't try to pull it away. It was warm, and rough, and enveloping. Her fingers curled around his hand to touch his knuckles.

He leaned back, murmuring in content, drawing her on top of him. Before she knew it, their hands were joined on his shoulder, her knees in the space between his crossed legs. His chin could rest perfectly into her shoulder, but he resisted from touching her with his lips, or face. She looked down, at his ear, and then back at her legs. "Um. Mark. This isn't comfortable. Or friendly."

He tilted his head to observe her position. "You legs are long."

She reached back to massage her aching calves, and leaned so she wasn't resting on her knees anymore. "It comes with being tall." She rearranged herself so she mirrored him, sitting with her legs crossed.

He touched the red spots on her knees, rubbing them. He wasn't really looking at her, but she felt compelled to pull her dress farther down. Unintentionally, she exposed more cleavage and realized the double-edged sword of modesty and style. "Can we go…?" She pointed out the door of the cramped bathroom.

He nodded, and they both scooted into a kneeling position. Mark struggled to stand up and not kick her at the same time, almost pulling them both back down.

Addison laughed and asked, "When did we get so old?"

"I don't know," he chuckled.

Eventually, they both straightened up into a stable stance. Once again, Addison found her hand on his upper arm. It wasn't necessary anymore, but her fingers lingered, feeling his strength through his t-shirt. She wondered if he picked that kind of shirt on purpose, just to make her look.

Her fingertips drifted down his arm and barely tickled the crease of his elbow before dropping down to her side. His whole body twitched and he took a deep breath, pushing past her to leave the suddenly stuffy bathroom.

She followed him into the living room, where it was much easier to breathe. He stood with his back to her and she didn't make a move to catch his attention. Her wandering mind noticed the moonlight for the first time, shining on the eggshell colored carpet. She knew Mark couldn't have picked out that carpet. That was the work of Carolyn Shepherd.

She smiled at the thought of her mother-in-law. She loved Derek's family, Mark included. Lately, though, Mark and Nancy were the only Shepherds she'd seen in months, since Thanksgiving at least. They didn't get to drive up to Connecticut as much, because of work.

The loss of contact caused an ache to resonate in her chest. Mark was breathing more quickly, and she wondered if he was thinking about the same thing.

Fatigue hit her like she had slammed into a brick wall. In interest to find a soft surface, she moved behind him and let her feet thud against the carpet in order to make her presence known.

He heard her behind him, so he didn't jump when she brushed against his elbow.

"I'm tired," she mumbled, "I'm..hmm…sleep." She rubbed her eyes.

Mark gazed somewhere outside for a moment, and then jolted back to reality. "Yeah." He grabbed her and shook her awake. "You're staying, right?"

"I'm sleeping." Her eyes remained closed, and her hands stretched out in front of her body. "Where's the floor? It was just there a minute ago."

Completely disoriented, she tried to fall forward and lie down. He caught her, pulling her towards the bedroom. "Good. Because I wouldn't let you leave."

"Thanks." She was in his bed without knowing exactly how she got there. Her face pressed into the pillow for a few seconds, and she threw her arms down on it, propelling herself up. "I'm suffocating!"

"No, you're not."

A pair of sweat pants hit her face. "You're trying to suffocate me!"

"I'm trying to dress you."

Addison cracked her eyes open. The lights blinded her. "Oh!" She twisted to plant her face back into the pillow, but smacked her head against the wall instead. "Damn it!" she screamed.

"Uh-oh. Addison. Can you hear me?" She didn't respond. "Please don't have a concussion. Where's Derek when you need him?" Mark brushed her hair out of her face before deciding just to redo her ponytail. He pulled the scrunchy out gently and ran his fingers over her scalp until she stopped crying.

"I miss Derek." Her eyes opened, watery and red.

He wiped away the hot tears on her face. "Can I put these pants on you?" He held up a pair of large black sweatpants.

They looked so comfortable and soft, so Addison drew her feet up and poked her toes in. "Don't look."

Mark looked, but he did the rest of the work, bending her knees, pulling the pants up. "You want a t-shirt?"

Addison thought for a moment, and then felt the sheets under her hands. They were scratchy. "Yes."

Mark found a seemingly clean shirt on the floor, and held it to her. He examined the back of her dress, attempting to figure out how to get it off. "How do you want to take this thing off?"

"I don't think so." She pinched her nose and pulled the t-shirt over her head.

Mark threw the covers off of her, which allowed her to swing her legs over the side of the bed. He yanked down the dress, and stood back up. He helped her crawl back into bed. She rested, unmoving, and watched him as he reached to rub her foot.

His hand snapped back before their skin made contact. He repeated this again with her waist and her shoulder. Only when he grazed her hair did he actually touch her. He pulled her hair back with the scrunchy and she smiled. "Thanks."

"Yep." Mark shut off the light and climbed into bed with her.

Addison pulled the covers up over her and turned to face Mark. "Do you want me to sleep on the couch?"

"No. Stay here." He faced her and rubbed her arm.

She tucked her hands under her cheek on the pillow. "I feel like this is kind of inappropriate. You're my husband's best friend. I shouldn't be here."

Even in the dark, she could see him struggling. He didn't want to say anything, and she felt badly that she had hurt his feelings.

He spoke slowly, trying to control his volume. "I miss him too." He gripped her arm tightly. "I haven't seen my best friend in three weeks. You remind me so much of him, and I just- I don't really talk to anyone else. So if you could just stay, that would be good."

She kept her legs closed. She didn't have sex with him, but she hugged him.

After that, they were inseparable for the rest of the night. She wrapped her arms around his neck, and his circled her waist. They fell asleep like that, and only rolled over to sleep on their sides, but they didn't let go of each other.

Mark woke up early to make the pancakes, but as he finished mixing the batter, he decided to throw it out. Addison already felt like she was just another of his one night stands; the special treatment and pancakes would just make it worse.

He needed a real friend, and apparently Derek had deemed both of them unworthy of his presence. It was bullshit. They all knew it. Mark told himself that he would have to call Derek and confront him.

Later.

Right now, he wanted to make breakfast for the pretty redhead in his bed. He thought about eggs, but that would require too much effort. It might look like he tried too hard. So, he settled on cereal, pouring two bowls. It felt like a friendly gesture, no romance.

He didn't carry the bowls on his special breakfast-in-bed tray (the one with flowers, he wasn't ashamed to recognize.) But was difficult to balance them and a banana without spilling. He set them on his bedside table, and climbed back into bed.

Her legs squirmed against his at the movement on the mattress. She rolled halfway over to face him, but her eyes remained closed. They darted left to right under her eyelids. He wanted feel that against his lips. Bad idea, he knew.

But, God, she was a really beautiful woman. And Mark loved women. More than surgery. He loved the smooth skin on her arms, her pink lips, her legs. He really loved her hair. All that red, now a curly, tangly mess. The scrunchy was on the floor somewhere, and, for once, he didn't care. He wanted to just pull at the ends, and that t-shirt that he'd given her was turning out to be a big mistake. It was definitely creepy, but he couldn't stop staring at her boobs, stretching across his shirt. Had it shrunk in the night? Not possible. Maybe the morning light made it easier to see. Or maybe he just wasn't afraid to look, now that she was asleep.

He looked away; he couldn't do that to Derek. They were just normal boobs, he convinced himself. Nothing special about them. In fact, he'd probably get to see a better pair in the flesh that night. But he wanted to touch these. Right now.

He'd gotten so close last night. Then he fell asleep.

It would have to be sneaky, so he could claim that it was an accident if she woke up. He put his hand on her upper arm, almost wrapping around it. His thumb brushed the side of her arm, then the side of her body, then...

"Mark?"

He pulled his hand off of her quickly. "Uhhh..."

She squinted at him. "Have you been here the entire time?"

"Breakfast." Now that she was awake, it really hit him. This was Addison, Derek's wife, in his bed, her hair splayed across his pillow. "I brought you some cereal. You can have it whenever you want."

"Thanks." She looked cute in the morning. He'd seen her in the morning before, back when he still roomed with Derek, but she never even left the bedroom unless she combed her hair a little and wiped the leftover makeup from her eyes. "My back hurts," she complained, as if noticing all of a sudden. She turned on her side and reached behind her to feel the sore muscle. "I think I slept on it wrong."

He scooted closer, and she didn't say anything so he put his arm around her, the crook of his elbow resting nicely on her side. "Where does it hurt?" He pressed a little into the skin of her back.

"A little lower." He moved his fingers down the bumps of her spine utnil sher eyes closed. "Hmmm," she moaned.

A little hiccup of laughter escaped his mouth, and instantly he wished he could have taken it back.

"Okay." Her eyes snapped open, and she pushed away from him.

He wouldn't let go. "Stop," he begged, with a smile on his face. It wasn't his fault. He had to laugh- she was practically faking an orgasm in his arms.

She placed her hands against his chest and pushed again.

But he was stronger.

She hit him playfully. "Let me go! I'm embarrassed."

"Don't be." She relaxed and he put his hands back on her lower spine. "I promise I won't laugh again. It was funny only for a second. And it's my fault anyway. I haven't flipped the damn mattress in fifteen years."

"I don't even care anymore." She snuggled warmly into him. "Feels good."

"Good." He tried to keep up exactly what he was doing, moving his fingers in small circles against her (well, his) t-shirt.

After a few deep breaths, she looked up at him and admitted, "I acted like a child last night."

"It's fine." He meant it. He'd never hold something like that against her.

"I shouldn't have thrown a tantrum." Obviously, she'd thought about this a lot. He hoped she hadn't lost sleep over it. "I'm sorry."

She didn't have to be sorry, but it made him feel better that she thought of him, and how he might perceive her. At least he wasn't invisible. He wanted to be good friends with her, with real apologies and inside jokes and everything. "It's okay." He really didn't know what else to say.

"I really appreciated what you did last night. I'm glad you were at the party." She propped herself up on her elbow, but made sure that he could still reach her.

Mark couldn't believe it. Was this a girl who actually said what she was thinking? He thought he'd never find one. Well, the blonde women that shared his bed every other night usually said what they were thinking, but he didn't know if one-word commands counted as thoughts. He guessed he just had that effect on women.

Except for this one.

"Hey, you saved me. I would have ended up with a mindless married twenty-year-old if it weren't for you." He meant to cheer her up, that it was a good thing that she came home with him to watch Al Pacino, but somehow it sounded better in his head.

She smiled sadly. "Aw. I'm sorry." She lightly smacked herself in the forehead with her palm. "I completely crashed your date night. And you didn't even get lucky."

"That's not what-"

"I know." She held his hand and squeezed it reassuringly. "But just because my husband ditched me for a ventriculostomy doesn't mean that you should have to give up sex on a Friday night."

"I didn't give up anything!" She was thinking the exact opposite of what he wanted her to think. He wanted her thoughts to be happy when she thought of him, not lonely because of his stupid best friend.

He really was just a substitute. "Please. I'd rather spend it with you." Wow, he really sounded like a woman now, actually admitting feelings and all.

"Okay." She touched his cheek in thought, and then tapped lightly on his chin. "Prickly. You need to shave." She let her legs drop out of the bed and stood up. "We're on for next weekend right? Godfather II?"

He was speechless for a second. "Yeah..." He shook the uncertainty off- Al Pacino was never uncertain. "Sounds good."

"As long as you don't mind." She winked.

He continued not to mind, but actually enjoy her presence through the next few weeks. After finishing the Godfather series, they needed more movies. Friday nights were their nights. They started only going to charity events and cutting out early. Addison got excited opening pretty envelopes with calligraphy, and Mark felt like all the money he'd been donating was making up for his past bad karma. But then they didn't even bother. Addison brought the pizza and Mark rented the movies, if he didn't have them already.

In the middle of Righteous Kill, Addison realized that this was the last movie. No more Al Pacino. They watched every movie, and stayed up late in the night. They talked, and joked, and apologized. Just like a real friendship.

And Derek never noticed.

A/N: All right. Random idea. I'm in a Maddison kind of mood and I just really want to write this story.

Best part? It never has to end!!! That's right: I have no sort of outline for this thing.

I'm so excited for the crossover. Except I hope it's not awful. Grey's has been disappointing me lately.

YAYAYAY for maddison! Review, please.