Meredith found her target exiting a patient's room, and she sped up, walking quickly down the hall to catch up. He looked at her sideways when she fell into step with him, raising his eyebrows as she smirked humorously. "Hey," she greeted.

Mark smirked back. "Dr. Grey."

She wiped the unprofessional grin from her face as two orderlies passed by, but when they were out of earshot, she peered at Mark once again, her eyes twinkling. "So…you and Izzie?"

He nodded in confirmation, unable to prevent the smile that came to his face at the thought. "Me and Izzie."

"How'd this happen?"

He stopped walking, turning his body so that he was looking at her. "Isn't this something that you should be talking to her about? I'm not really up for girl talk, Grey."

She laughed, shaking her head lightly. "Yeah, I guess you're right." She grew serious moments later, looking at him pointedly. "You better not be using her, Mark. Izzie is the kind of person who gets attached quickly, and once you've awakened the beast, it won't be long before she-"

"Awakened the what?"

Meredith grinned at his look of perplexity. "The beast, Mark." His confused frowned deepened, and Meredith opened her mouth to explain, but closed it once again when she caught sight of Derek walking determinedly toward them. Meredith rolled her eyes as he approached. "I'm so not doing this right now," she muttered, turning quickly on her heals and fleeing down the hallway.

Derek sighed as he walked up to Mark, his eyes following Meredith as she escaped around a corner. "Well, that was mature."

Mark chuckled. "Please don't tell me that you expect maturity from Meredith."

Derek glared at him. "Well, I expect her to talk to me. I want to fix this, and I refuse to accept the idea that she fell out of love with me overnight."

"You're right; she didn't. She wouldn't care so much about you and her sister if she didn't still have feelings for you."

"There's nothing going on between Lexie and me," he snapped.

Mark rolled his eyes at Derek's defensive tone. "I know that, but you have to prove that to Meredith. Just keep pushing her, Derek. I'm sure she'll come around eventually."

Derek frowned. "You're kind of freaking me out." At Mark's blank expression, he continued. "It seems wrong to be taking relationship advice from the man who, at one time, was sleeping with my wife."

Mark nodded. "Trust me, the irony isn't lost on me, either."

Derek glanced around, ensuring that the hallway was clear of nosy ears. "I'm sorry for, uh…attacking you this morning."

Mark laughed. "Don't worry about it. If I heard that you took Izzie home from a bar, I'd do the same thing."

Derek grinned at his words. "So you really have a thing for Stevens, huh?"

He looked up sharply. "No," Mark shrugged dismissively, suddenly looking uncomfortable. "I mean, maybe a little. Well, okay, maybe more than a little, but we're not, you know, in a relationship or anything. I mean, you know…we're involved, but we're not exclusive. Not that I would want to be with anyone else, because she's kind of a hand full all by herself. I'm not in love with her or anything like that; I don't even have feelings for her, really. Okay, well, maybe that's not true. She's just-"

"Mark, shut up," Derek said, raising his eyebrows at Mark's stammering. His mouth closed immediately, his face flushing, and Derek laughed. "Wow, look at that. I never thought I'd live to see the day when a woman would have the power to reduce Mark Sloan to the likes of a love-struck teenager."

Mark groaned. "I'm not love-struck, you asshole."

Derek grinned at his tone. His eyes left Mark's, glancing over his shoulder to see Izzie approaching them. "Speaking of the object of your affection…"

Mark rotated, his eyes meeting hers as she smiled at him. He turned back to look at Derek, his expression indicating that his presence was no longer welcome. Derek took the hint, nodding his head as his smirk deepened. "Alright, I'm leaving. But, uh, you want to grab a drink after work? Maybe you can share more of your newfound relationship wisdom."

Mark smiled, appreciating his friendly gesture. "A drink would be good."

Derek nodded, leaving Mark standing in the hallway, waiting for Izzie to catch up to him. When she did, she smiled at him, resisting the urge to kiss him in the open hallway. "Hey, you. I just wanted to see you before I left. My shift's over, and I'm about to head home."

Mark nodded, still frazzled by his semi-embarrassing conversation with Derek. "Um, okay."

Izzie laughed at his nervousness. "Are you alright?"

"Yeah, yeah I'm fine," he quickly replied. "I just have some patients I need to check on."

She frowned. "Oh, well okay then. Do you want to meet up later tonight? I can come over to the hotel after you leave the hospital."

Mark shifted nervously on his feet as Derek's comment about being love-struck ran through his mind. He wasn't love-struck, was he? Surely not. Mark Sloan didn't do love-struck. "I actually have plans after work. Derek and I are going to get drinks."

Izzie's face fell with disappointment. "Okay, well maybe afterwards then."

Mark nodded, reaching into his pocket and pulling out his wallet. From it, he produced a plastic keycard. "Maybe you can come by around nine o'clock; I should be back by then, but if I'm not, here's a key to the room."

She pursed her lips, still frowning at his odd behavior. "Okay, thanks. Um, have fun with Derek."

He smiled slightly, trying to think of something clever to say to redeem himself for being lessened to a stammering fool. His mind was blank, though, so he simply walked away, leaving Izzie staring confusedly after him.

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Mark whistled happily as he walked down the hallway towards his hotel room. Drinks with Derek had gone well; better than well, actually. They'd spent much of the night reminiscing over memories from their childhood, even having a few chuckles over the fun times had after Derek had gotten married. Any tension between the two of them was temporarily forgotten as they consumed their fair share of Joe's supply of scotch, their conversation eventually evolving to include the women in their lives.

It was only eight o'clock, a full hour before Izzie was supposed to arrive to the hotel, but as Mark approached his room, he couldn't help but hope that Izzie was already there. He knew that he wasn't in love with her; it was too soon for that, and he would readily admit that they didn't know one another all that well. His feelings for her were unlike anything he'd ever experienced, though, because he actually found himself wanting to know her. He wanted to know everything about her; her childhood, her likes and dislikes, her hopes, fears and dreams. He knew her body like the back of his hand, but he suddenly found himself want to know more than that. He was hesitant to admit it, but Mark found himself actually wanting to try this relationship thing that Izzie seemed to be so fond of.

He pulled out the new keycard that he'd gotten from the lobby, opening the door of his room and freezing in the threshold. His mouth fell open slightly as he stared at the woman sitting on his bed sipping a glass of champagne, outfitting in only a robe as her wet hair dripped onto the fluffy cotton terrycloth. She smirked at him when she saw him in the doorway, uncrossing her long legs and standing up from the bed.

"I thought you'd never get here," she murmured. "I used the key you gave me to get in."

He frowned, shutting the door behind him with a sigh. "What the hell are you doing here, Addison?"

The smile fell from her face at his wary tone. "Things are already crazy in Los Angeles, and I just thought-"

"And you thought you'd pay a visit to your personal manwhore? You thought that you could just leave Seattle, but that I'd be here waiting for you whenever you needed to get laid?"

Addison looked down shamefully, staring nervously at the glass in her hand as she struggled to find something to say. "I'm sorry. I didn't realize…I mean, I thought…"

He sighed, his expression growing remorseful as she trailed off. "Sorry, I shouldn't have snapped at you. I'm just surprised to see you here."

Addison nodded. "I know, but I needed to get out of Los Angeles. It's already not what I was hoping for. Apparently there are no cities in the world that are free of drama and heartache."

Mark chucked, kicking off his shoes. "No truer words have ever been spoken, Addie," he murmured, giving her a small smile as he walked to the bathroom. "Okay, let's talk after I take a shower, alright? That'll give you time to get dressed. You can't be in here dressed like that," he said dryly, eyeing the robe with the knowledge that there was nothing beneath the material.

She tilted her head, watching him intently. "Wow, you sure have changed in a short period of time."

He smirked. "You have no idea," he commented, shutting the door behind him as he entered the bathroom.

Addison smiled confusedly at the door for several moments. When she heard the shower cut on, she laughed a little, shaking her head in bewilderment as she wondered what in the world had gotten in to Mark.

She set her glass of champagne on the nightstand by the open bottle before walking over to the armchair in the corner of the room. She slipped the robe from her shoulders, allowing it to pool at her feet as she picked up the black lacy panties that were folded atop her clothes, pulling them over her hips.

As she fastened the clasp to the matching bra, she jumped with surprise, startled as the door of Mark's hotel room flew open behind her.

Addison turned around quickly, wholly aware of her near-nudity as she stared at the shocked woman standing in the doorway. "Dr. Stevens…" Addison mumbled with a mixture of surprise and embarrassment.

Izzie's couldn't move, her chest aching at the sight of Addison Montgomery standing in Mark's suite, dressed only in her black, overly expensive lingerie. Addison looked nearly as astonished to see her standing in the doorway, and Izzie shifted her eyes awkwardly. She inhaled sharply as her gaze landed on an open bottle of champagne sitting on the nightstand, standing tall over the crystal champagne flute stained with dark red lipstick. "I'm sorry Dr. Montgomery, I should've…I mean, didn't know that you…I was just looking for Mark…um, for Dr. Sloan, and I…"

Addison quickly picked up her robe from the floor as Izzie stuttered nervously, still standing dejectedly in the doorway. "Oh, Mark is here. He's in the shower…" she told her, pulling the robe over her body.

Izzie's eyes suddenly burned with tears as she became aware of the sound of running water coursing through the walls. She nodded, trying to keep the moisture from spilling over her lids. "Right…okay. Well, um, you know what? Just…just forget that I was here, okay? I'm sorry to bother you…"

Izzie couldn't get out of the room fast enough, pulling the door closed before racing down the hall. She raced to the stairwell, unable to bear the thought of waiting for an elevator on the same floor as Mark and Addison. She now knew why Mark had acted so strangely in the hallway of Seattle Grace earlier that day; he knew that he'd had plans to shack up with the fiery redhead only hours later. She couldn't believe she'd bought his lame excuse about meeting Derek for drinks. He wasn't meeting Derek; he was fucking Addison Montgomery. And what was worse, he was planning on bringing an unsuspecting Izzie into his bed immediately following his tryst with Satan. That bastard. And to think, she never would have suspected had she not arrived at his hotel half and hour earlier than he'd expected.

The ride home was a blur. Tears fell from her eyes as she drove to the house on autopilot, barley seeing the road as she steered the car through traffic. When she walked through the front door, she was met with the curious stares of her roommates, all of whom looked up sharply when they heard the front door slam behind her.

Meredith frowned when she saw Izzie's tearstained face. "What's wrong?"

Izzie shook her head. "Nothing, I just need to be alone" she muttered, hurrying quickly toward the staircase before anyone could ask her further questions. She ascended the stairs two steps at a time, locking herself in her bedroom and throwing body against the mattress. She let the tears flow freely, a sob escaping her mouth as she buried her face against the plush pillow beneath her head.

When her cell phone began to ring moments later, Izzie rolled her eyes, taking a shaky breath as she pulled the shrilling device from her bag. Predictably, Mark's name was flashing across the screen, and Izzie hit the ignore button, unwilling to listen to any of his pathetic excuses.

She didn't know why she was so upset about this. It wasn't as though she and Mark had made any sort of commitment to one another. They weren't involved in a real relationship, and there were certainly no rules between them. If Mark wanted to sleep with Addison, that was his prerogative. She had no right to be angry.

But she was. She was immensely angry. And jealous and bitter. And hurt. Izzie Stevens felt more hurt than she had in a long time. She felt even more hurt than she had when she'd been rejected by George, even more hurt than when Callie had thrown the fact that they were starting a family into her face.

Izzie had an incredible urge to heave her phone against the wall when it began to ring again. Didn't he get it? Didn't he understand that she didn't want to speak to him?

She sighed with relief when the ringing ceased, ignoring the voicemail notification as she turned off the power of her phone.

There simply was nothing he could say that would make her feel better about finding his ex-lover standing virtually naked in his hotel room. No sir, there was no way to fix what he'd broken. They were through.