Alex paced back and forth across the worn carpet in his bedroom. His plan had been to stay in his room until Cristina left for work and then to avoid both her and Addison Montgomery for the entire day.

But the plan would only work if Cristina left her room first.

It would not work if she had the same plan.

Alex slowly eased open the door and slipped silently into the hallway.

Six feet away Cristina was doing the same.

"Damn," he breathed.

"Oh for…" Cristina exclaimed slamming her door the rest of the way. She faced him, her hands on her hips, "So what?" She demanded.

"I don't know."

"Well it's not happening again," Cristina said pointedly.

"I don't want it to," Alex stated firmly.

"Well good. Cause it's not."

"Fine."

"Ok."

"Fine."

"No more sex," Cristina emphasized, "I can keep living here and it will never even come up."

"Fine," Alex nodded, "Do you need a ride?"

"Yes," Cristina reached back inside her room and grabbed a jacket, "So I can seriously keep living here?"

XXXXXXX

"Where are you?"

Addison took a sip of her drink, "Parking lot of the 7/11. Where are you?"

Callie stabbed at her egg, "Denny's. What are you doing at a 7/11?"

"I needed a Big Gulp."

"Why?"

"Hung-over," Addison took another sip, "George took you to Denny's? That's… cute."

"No," Callie corrected, "Callie was hung-over and needed greasy breakfast food away from George's peppy people, so Callie took Callie to Denny's."

Addison chuckled, "You flew the coop."

"You know," Callie said thoughtfully, "They are kind of like chickens. Izzie kinda clucks, Meredith bobs around all hen-like, Derek is like a rooster that scratches everyone that comes near him."

"And I bet he wakes up the entire house at ungodly hours," Addison teased.

"You know he does," Callie sighed, "I need out of that house."

"So get out," Addison pulled into the hospital parking lot, "You lived in the basement of the hospital for months, I'm sure you can find something."

"Unless Meredith's house has some magical vortex where we can have our own place but George does not have to physically move out; I think we are suck."

"I need to go to work," Addison groaned turning her car off.

"Did you ever get your booty call with the young willing-to-impress intern?"

"No," Addison stepped out of her car, kicked the door shut and started towards the hospital Big Gulp in hand, "He was probably saving Yang from a bout of alcohol poisoning."

"Saving," Callie bit into her toast, "Or inducing."

"Alex doesn't drink."

"Hmm. A first name and a personal detail; this is serious."

"I'm hanging up now."

"What do you think of attics?"

"They're dusty and rat-infested."

"That's basements."

"Dusty and bat-infested."

"I can live with that," Callie nodded decidedly, "Have fun at work."

XXXXXXX

Cristina leaned against the station counter grateful for the solitude. Meredith meant well, but where Meredith was, Izzie was and George was; and Cristina was not in the mood to be dealing with all those people.

She looked up as Addison sat down in a chair further down. Addison smiled at her encouragingly and focused her attention on the papers that she was reviewing. Cristina didn't smile back her stomach clenching nervously.

George set his charts down on the counter beside Cristina. Cristina stared ahead in frustration and then turned her head to glare at him.

"I," George avoided Cristina's gaze, "don't know why I'm standing here…"

Meredith arrived, pressing herself between George and Cristina. She watched Cristina silently.

"What?" Cristina asked tersely.

"I borrowed Derek's car," Meredith said, "I'll help you move your stuff out of Alex's."

"Ya," Derek added, appearing at her other side, his voice void of enthusiasm, "We would love to have you back."

"I think I'll stay where I am for now," Cristina said evenly, praying that all these people in particular would go away. She caught Alex's eye as he rounded the counter and saw the assortment of people gathered around the nurse's station.

This could turn out very very badly.

Meredith glanced at Alex, and lowered her voice, as she spoke, "You don't want to stay with him He's just going to try to sleep with you."

"Well, we have that in common."

"Hey," Alex said quietly leaning against the counter near Addison.

"Hey," Addison swiveled her chair towards him, "I called you last night."

"I know," Alex forced a coy grin onto his face, "I just checked my messages."

Addison pursed her lips and smiled suggestively at him.

Meredith furrowed her brow at Cristina, "What are you…"

Cristina inhaled sharply and turned her back to everyone, Meredith turning with her. Cristina lowered her voice to barely a whisper "I slept with Alex."

Meredith eye's widened.

"You slept with Alex?" George exclaimed loudly.

All heads snapped toward George.

"Sorry," he murmured.

Cristina turned and met Addison's even gaze. Cristina lowered her eyes guiltily.

"Right," Addison murmured under her breath, standing hastily.

"Addison," Alex said apologetically, "It wasn't…"

Addison ignored him, intent on leaving.

"Addison!" He protested louder,

"Addison?" George smirked, "What? Did you sleep with her too."

Addison froze. All eyes focused on her back. Taking a deep breath she squared her shoulders and walked away.

"George!" Cristina and Alex exclaimed simultaneously.

George's jaw dropped, "You slept with Dr. Montgomery!"

XXXXXXX

She paused and glanced around; there was one within earshot. Everyone was probably down the hall, listening to the latest gossip. She took a step inside the room and closed and locked the door.

"Mark," she said slowly.

Mark glanced up at her and smiled, "I knew you'd come back eventually."

Addison forced a smile, putting up a coy front, "Did you?" She asked, slipping her lab coat off her shoulders and dropping it seductively on the floor.

He smirked, "You always have before."

She didn't react to this, just lowered her eyes to his belt buckle and nimbly undid it, watching him through her lashes.

"Hey, not that I don't like that," he teased as his pants pooled around his ankles, "But why are you the only one having any fun?"

She sighed heavily and began untucking her black blouse.

He touched her chin lightly, lifting her face to look him, "Let me," he said softly. His hand skimmed down her neck and breast bone, undoing a few buttons at the top of her blouse before sliding down her stomach and under the hem of her shirt and sprawling across the bare skin of her waist; his other hand lightly massaging up and down her thigh and hip. He dipped his head to kiss her, smirking when she turned her face at the last second, "Tease," he murmured settling for the skin right below her jaw.

Addison rolled her eyes at his comment, pushing at his chest slightly as she started on the buttons of his shirt.

Suddenly she took a step back.

She stared at his chest ignoring his hands, which were trying to pull her back.

"Damn it Mark, " she groaned, "Damn it!" she exclaimed again, tucking her shirt back in and twisting out of his arms.

"What?" Mark demanded, confused and more then a little frustrated with the sudden turn of events.

"You have a god damn hickey Mark!" she exclaimed, "Damn it," she said again trying to hold herself together as she walked to the door, "Just… ugh!"

The second that the door close behind her, her name was being called from down the hall.

"Addison!"

Addison turned immediately and began walking briskly in the opposite direction.

"Addison!" Alex caught up with her in an instant, grabbing her arm, "I was going to tell you."

Addison tried unsuccessfully to wrench her arm out of his grasp and scoffed, "You were going to tell me that you slept with Cristina?"

Mark stepped out in to the hallway, "Let her go."

Alex ignored him, but also didn't say anything in response to Addison's question.

"I didn't think so," Addison spat bitterly, trying again to pull free from his grasp.

"Hey," Mark stepped between them facing Alex, "Let her go.'

Alex reluctantly released his hold on Addison's arm and she immediately turned and quickly walked away.

"Addison," Alex protested, trying to step around Mark, "I'm sorry."

Mark stayed where he was blocking Alex's way. He heard the door to the stairwell open and close indicating that she was now out of earshot. He crossed his arms, "You know," he said slowly, "Maybe I didn't give you enough of a chance. I'll talk to Bailey, you'll be back on plastics by the end of the shift." he smiled, "We are going to have so much fun."

XXXXXXX

Addison sank down on to the bottom step and buried her face in her hands. It was taking a tremendous amount of self-control not to cry.

Rapid footstep approached the stairwell and the door flew open. The footsteps stopped abruptly and silence filled the stairwell as the door slowly shut.

Addison looked up and sighed, "Go away Derek."

Derek smirked at her and moved past to walk up the stairs, "Karma."

Addison buried her face again, "Screw you."

Derek paused, "Excuse me?"

"I said," Addison repeated evenly, "Screw. You."

"No. I heard you. I just…"

"I know I started it," Addison cut him off, her voice starting to break, "I know that. But it doesn't make it okay."

Derek turned slightly to look at her.

"I cheated once," she continued, "But now… Now every man that I'm with seems to think that it's okay. That it won't hurt me. But…"

Derek slowly walked down the few steps between them and sat down beside her.

"It's not fair," Addison finally broke down, allowing the tears to escape her eyes, "It's not fair."

He watched her cry for a few minutes, her bent shoulders trembling. Tentatively he angled his body towards hers and placed a hand on the top of her back near her neck.

She moved to shrug his hand away, sitting up and staring at him.

He met her eyes and looked at her sadly, his hand still resting lightly on the back of her neck.

Her face slowly crumpled. She leaned forward until her cheek rested against his chest and she continued to cry softly.

He was still for along moment, unsure what to do. Instinctively his hand started rubbing small circles on her back and he lowered his face so his cheek rested against her forehead. She cried steadily, never escalating into sobs, just stagnant cries of sadness.

The door opened and Derek looked up, "Go away Mark," he said quietly, returning his attention to Addison.

"Addison," Mark ignored him, taking a step forward "Addison. Stop crying."

"Mark!" Derek repeated indignantly. He couldn't believe the insensitivity that Mark was displaying. He stared hard at him.

"Addison," Marked said again, kneeling down in front of her, "When we were in New York and you found out that I was sleeping with that woman did you cry?"

Addison pulled away from Derek slightly and looked at him, "Which one?"

"Addison…" Mark chastised lightly, "You didn't did you?"

"No," she replied tearfully.

"And when Derek left," he said gently, "And you had to go back to work and everyone knew that he left you and everyone knew why, you didn't let anyone see you cry then did you?"

She shook her head, "No."

"And when you," he paused, this was either going to help or push her over the edge, "When you found Meredith's panties in Derek's jacket, and you knew that he had been with her; did you let them see you cry?"

Derek slowly dropped his hand from where it still rested on her back.

Addison was silent.

Mark leaned closer, "You let them see you drunk, very very drunk but you didn't let them see you cry, did you?"

"No," she whispered.

"So why would you let them see you cry over someone as insignificant as Karev?"

Addison nodded weakly.

"Ok," Mark touched her knee for a moment, then stood. He reached down and pulled her to her feet. She let him, her body limply allowing him to lead her. He shook out her lab coat which he had been carrying with him when he found her, and slide it up her arms and over her shoulders, "You need to go wash you face," Mark instructed softly treating her gently as if she was a small child, straightening her coat and buttoning the buttons of her blouse, which Derek was just now noticing were open to an indecent point, "And you need to tough out the rest of the day."

Addison nodded, mustering up a small smile for him as she left the stairwell.

"She's sad," Derek said slowly, as if this was a completely new concept for him.

"Yeah," Mark scoffed, "She's sad."

"I've never seen her sad like that." Derek shook his head.

"Really," Mark crossed his arms over his chest and started down the stairs, "I have. And it's usually your fault."

XXXXXXX

"Could you believe today?" Meredith slid between the sheets and stared up at the ceiling, "And after all that Cristina is still staying there."

Derek didn't reply, he was lost in his own thoughts.

"Could you imagine if they actually…" Meredith grimaced, "Lets hope that that was a one time thing, because Cristina and Alex in a relationship… that's like a sign that the apocalypse is very very near." Meredith paused and replayed the day over in her head, "I can't even picture Cristina without Burke, let alone with Alex. And then you throw Addison into the mix…"

Derek turned his head slowly and stared at her profile.

"Did you know?"

Derek slowly shook his head, he was barely listening too her.

"Her face when George blurted that out, I can only imagine what he expression must have been when…"

"Meredith, stop," Derek said in a low voice, staring up at the ceiling again.

Now Meredith turned to stare at him, "What?"

Derek didn't reply.

"I'm sure she is fine, Derek."

Derek rolled onto his side away from her, "She's not fine."

"Well it was kind of bitchy of Cristina since I guess she knew, but," Meredith's mind was already wandering to something new, "Addison probably moved on by lunch. Izzie is worrying me though; she hasn't said a word about it. That could be awkward for a while, Cristina and Izzie. Maybe it's for the best that Cristina didn't move back in. I don't think that I could have handled that. And did you notice that Callie moved all of her and George's stuff into the attic? She is so strange…"

"Meredith," Derek said evenly, "Go to sleep."

"What is wrong with you?" Meredith demanded, completely confused by his lack of interest.

"Nothing." Derek closed his eyes, "It was just a long day and I have an early surgery scheduled."

"Oh," Meredith shifted closer and kissed the back of his neck, "You should have just said so."

It was hours later when Derek finally fell asleep, his mind plagued by inexplicable feelings of guilt. His mind flashing to Addison sitting heartbroken on the stairs because yet another man had failed her.

He wondered, if he had known 3 months ago that Addison would be sitting on those stairs, crying, still hurting because of the way that he had left her; would he still have followed Meredith into that on-call room?