Hey guys! Thanks for the reviews so far. Yes, so far I am planning on this being a Maddison fanfic! But of course, like I said TWISTS will be happening. What I mean by pairing is that Izzie is going to be working with Mark, helping him get better…I wish I knew how to reply to reviews. LOL Thanks for the reviews! Here's the next chapter.

Celibacy

Izzie showed up at Mark's office door at 8 am with her own coffee and donuts and a slip of paper. She knocked on the door and waited, when no one answered she walked in and turned on the lights and started laughing. Mark had indeed cleared off his desk and in the middle of it was a notebook with bright lettering saying, "IZZIE'S TIPS FOR A BETTER MAN."

Izzie shook her head and moved to the desk sitting down in the chair and leaned back taking a bite out of her donut. She had made a list last night with Meredith about what makes a relationship better and she came up with exactly 25 things. She narrowed down the important things though and the lesson of the day could make or break Mark. She hoped he was up to it!

"Where's mine?" She heard and turned seeing Mark walk in with only coffee. "You get yourself donuts but not me? I feel left out!" He shut the door behind him and then moved to the desk sitting down and taking a drink out of his coffee looking at her.

They were both quiet for a moment, taking each other in. Izzie didn't know where to start and Mark was just wondering how long this would take.

"What's my first lesson?" Mark finally asked after a few moments of silence.

"Celibacy…"

Mark had chosen that moment to take a sip out of his coffee. When Izzie said that word, that word that he had never, ever practiced in his life. It shocked him and he just started choking, his eyes watering, his face turning red.

Izzie started cracking up and held her stomach looking at him. She pulled out her camera phone and clicked a picture, reminding herself to send it to Addison later. She wiped away tears from her eyes, giving herself a point. She knew Mark would be surprised by the first lesson, but wow! She could have not planned it better. The hardest lesson should be out of the way and he should probably practice it.

Mark just started shaking his head trying to regain his composure. This girl was absolutely insane! Celibacy? He practiced that until he lost his virginity at 16. The longest he went without sex was 2 weeks and that was when Addison left him. He was miserable the first week and then the next sick.

"If you want Addison back, you better show how serious you are. And being celibate and waiting for her, is a great way to start!" Izzie took a drink out of her coffee smirking. The test was on. "Do you want her back Mark?"

Mark's face was still red and he was glaring at her. He stood up from the desk, hating the fact that she was right, and he wanted to wipe that smirk off of her face. "Dr. Izzie Stevens… You really think my sex life, outside of this hospital, which Addison never sees or hears, really has impact on changing me?"

"Oh yeah…" Izzie nodded and stood up too setting the piece of paper on the table. He was treating her like his inferior again, but he wanted her help and she was going to give it to him. He was going to have to take her seriously. "You want a serious relationship with her. She knows when you've slept with someone Mark. US girls have a way of knowing and finding out. You need to be celibate and I'll let you take time and decide whether or not you in this 100."

She headed for the door and then turned around. " Look over the paper…It's the reasons why you should be celibate for this." Izzie then walked out and headed to the nurse's station.

Mark sat back down and ran his hand through his hair and glanced at the paper. There were reasons Allright. He sighed and picked up the paper reading it over.

"Reason one…Sex, was one of the reasons you guys broke up. You cheated on her because you couldn't keep in your pants. Maybe if you kept it in, you might show her your serious." Mark started reading out loud and rolled his eyes at every other one. She had made pretty good points and he knew she was right. He folded the paper and stuck it into that notebook and then put the notebook up on his shelf and then headed out to do his pre-surgery check up.

GAGAGAGAGAGAGAGAGAGAGAGAGAGAGAGAGAGAGAGAGAGAGAGA

Mark spent the rest of the day flirting with nurses who went out of their way to walk by. His mind was on his first lesson though and he ended up getting bored after they moved up to him, their bodies just screaming, "Take me now, I'm yours." It was the chase that thrilled him, but today it wasn't enough.

After about the 12th time making up excuses about how he wasn't free that night he sought out Addison. He needed to see her, needed to have a reason set in his mind on why he should stay celibate and take this whole thing seriously. He headed to the nearest OR, knowing that's where Addison was finishing up her surgery.

Mark opened the gallery door was surprised to see pretty much ALL of Bailey's interns watching Addison's surgery, Even his own intern, Alex watching too.

"Dr. Karev." Mark cut through all of their laughing and chitchat. He smirked when Alex jumped up from his chair. "Shouldn't you be doing my charts?"

"Sir, yes. Right on it." Alex flew out of the gallery and Mark laughed a little at the glare on Izzie's face.

" You're a jerk, you know that right?" Izzie snapped and then turned her back to him paying attention to Addison's surgery. Meredith gasped and Christina elbowed her, a smirk on her face.

Mark didn't reply to Izzie for a moment just went over and sat down next to her, taking the seat where Alex had been sitting. He glanced at Meredith, Christina and George all exchanging looks and he knew they were probably all wondering what was going on between them. His eyes then moved down to where Addison was operating and he took a deep breath.

The last time he'd seen Addison perform surgery was the week before she left to go after Derek. He had made a point to. If he ever had free time and she was in surgery he would make sure to be there, waiting with coffee and a brownie for her after surgery refuel. Derek used to do that for her until one day he had asked Mark to do it while he went out of town for a week and he never stopped doing it after that week.

Suddenly Mark realized how much Derek had handed off to Mark to do. He had asked Mark so many times to show up in his place, For dinners, Movies, Dances, Banquets, walks in the parks, Sunday morning coffee. That's how it was the last year of Derek and Addison's wedding. It was as if Derek had filled up Marks' schedule and he never noticed. Addison was enough of a woman to keep him on his toes and she read him like the back of her hand. He never ever was late to anything she had set up with Derek and maybe that was why it was so easy for them to fall into a pattern after Derek left. That's what had scared him too. The pattern.

The pattern of sleeping with the same person every single night. The pattern of fixing the same dinners every other week and having the same person being there every single day. The pattern of saying I love you and the pattern of having sex every night before either one could sleep. The pattern of being a couple.

The 6 months before Addison and him had slept together they had basically became a couple during the day. When Derek would cancel on lunch or dinner Mark would be there. Pretty soon Derek didn't even have to ask Mark to go to lunch with Addison, Mark would just go. Derek never showed up to anything Addison did anymore and that's when they had grown closer. Mark was Derek to Addison and Addison was his everything.

Mark didn't ever really notice he was Derek's replacement until the night before he cheated on Addison she had done something that made it all click to him and it scared him away.

Addison was petrified of thunderstorms. It was one of those quirks only her family, Derek and he knew about. She could hide it pretty well when she was at the hospital but anywhere else, She couldn't. That night hadn't been any different and he had sped home early after hearing the first big clap of thunder. He raced inside knowing exactly where to find Addison and he did find her.

She was half asleep in his bed, wearing one of those annoying flannel, hard-to-unbutton-so-he-has-to rip-them-off, pajama sets. He didn't even bother to take off his shoes and just slid into bed pulling her into his arms. She had been crying and he wiped away her tears. It lightening suddenly and he realized she had been sobbing by how puffy her eyes were and he knew that the thunderstorm couldn't have gotten her this upset. He leaned down and kissed her forehead and she had whispered a name. And it wasn't his like it had been the past few months. It was Derek's.

He remembered Addison tensing up in his arms after she had realized what she had called him and that night was the first time he didn't have to rip off any pajama's to get her. She had taken them off herself, as if to apologize for calling him the name he had been working so hard to get her to forget. They had made love except that time it was different. He knew who he was making love to and she didn't.

The next day he had watched her just like he was watching her now and he had realized that he was in love with her, and it scared him, so he did the one thing he thought would make Addison not scare him anymore. He brought a woman home and had sex with them. Mark had needed to know whether or not he could have easy sex and not feel guilty about it.

Unfortunely though it didn't help. Mark couldn't help but notice on this woman that her hair was brown, not red, That the spot on Addison's neck to make her shiver, only made this woman squirm and it made him angry. That anger fueled him enough to keep that woman in bed until Addison came home. He had changed his mind about hurting Addison though once he heard her come through the door but he knew it was too late. The damage was done and his heart was broken.

Mark was snapped out of his memories by a hand waving in front of his face. It was Izzie's.

"Hey, Did you make up your mind about the celibacy thing?" Izzie asked once they were alone. She had waited for Meredith, George and Christina to get paged before she decided to talk to Mark. When he didn't answer she waved her hand in front of his face. He grabbed it and set it down on her lap.

"I'm not…" Mark trailed off as he met Addison's eyes. He recognized surprise in them and he smiled at her and nodded. They looked into each other eyes, sharing a small moment before Addison broke it off after the scrub nurse said her name and he knew, by that look, that there might still be hope.

Mark got up realizing he suddenly needed to go buy coffee and a brownie and he looked at Izzie. "I'll be celibate." 3 words he never thought he'd ever say were said and he walked out.

GAGAGAGAGAGAGAGAGAGAGAGAGAGAGAGAGAGAGAGAGAGAGAGA

It was the end of Izzie's shift and she had been called into Addison's office. Addison had shut the door behind her and told her to sit. Izzie sat down on the couch and looked up at Addison as she started to pace the floor.

"I don't want you to do this Izzie. I don't want you to try and change Mark…" Addison turned and started walking the other way, not looking at Izzie. "It's just a bad idea and if you try and change Mark, he's just going to change back. It's a waste of time."

Izzie frowned and shook her head but didn't say anything. She had witnessed Mark and Addison's interactions for the last part of the day. After Addison's surgery Mark had showed up with coffee and what looked like Chocolate Cheese Cake. She also noticed how Addison had refused it, but Mark left it on the counter anyways and Addison took them both and locked herself up in her office for a while saying she needed to reply to emails. Izzie had known better though. The rest of the shift Mark had come back twice wanting to talk to Addison but she had refused him both and it was Mark's consistency that was breaking down Addison.

"Did you tell him to show up for my surgery or? Wait don't answer that!"

Izzie couldn't help but laugh softly listening to Addison's rant and she leaned back crossing her arms. She waited until Addison had paused before standing up.

"Addison, He asked for my help and to be honest…I can't turn him down. When someone asks for help, so pathetically slick like he did, I have to be there. Now no. I didn't tell him that you'd be in surgery but he did agree to the first lesson. So he's going to stay celibate for you. Maybe this should be a warning." Izzie walked over to Addison and patted her arm a little. "Mark wants you. He'll do whatever it takes to get you so watch out."

Izzie turned and walked out of Addison's office. She'd have to stop telling Addison about her plans with Mark or else none of this would be a surprise. She never saw Mark watching Addison's surgery coming though. It was as if Mark knew what the next lesson would be and he was getting a head start.

Izzie's arm was grabbed and she was yanked into an empty on call room. She looked up seeing Mark. "You do realize if anyone walks in people are going to talk right?"

" Ohh, Already thinking about that I see?" Mark let go of her arm and held out the celibacy reasons paper. "I signed the bottom to show I understand Dr Teacher."

"I really don't think you understand celibacy though, so why don't you keep that. By the way, you took Addison off guard today. I am quite proud. Keep doing that, build up the stability." Izzie pulled her cell phone out of her jacket pocket. "I'm going to call you and make sure your alone tonight, so what's your phone number?"

"Why don't you just come over instead?" Mark couldn't help it, she was hot and he had autopilot when it came to hot women. The look on Izzie's face spoke what she was about to say and he held up his hand. "I'm going to work on being celibate… can I work on the flirting later?"

" I think that's something that's not going to change but okay! Number?" Izzie entered in his number and then wrote her number down to hand to him. "Call me if you ever think your going to stumble."

"So you can come over right? Help me take care of my…" Mark stopped realizing what he was about to say was deemed inappropriate.

"Aww See Mark! You can change that side. You just have to think. Oh… that might take awhile." Izzie winked at him before heading out of the room.

When she arrived back home she snuck past George and Meredith who were in the living room with Derek and went into her room shutting the door behind her. She turned on her computer and started working on her next lesson plan. She was obsessed now but she never thought she'd get such results from today. She had Addison scared and Mark working on not having sex. What an interesting month this was going to be!

(( Please Review!! If I get 7 reviews this time I'll work quicker! So far I'm hoping to post at least once every 5 or so days:D ))