A/N - Sorry, I meant to finish and post this yesterday, but I started reading Safe Haven. Long story short, I got a little too interested and read the whole book. Anyways, this chapter is a LOT longer than the rest of them by atleast 500-1800 words. I'm actually pretty proud of it. Let me know what you think!

Disclaimer - I used a lot of quotes from the show in this chapter and I just wanted to say I don't take credit for them. I just really wanted to use the scenes.

"So, what are we going to do?"

"We're going to show them you and I aren't a mistake."

"Oh, and how do we do that?" Lexie asked, chuckling a little.

"Well we'll just keep doing what we're doing." He said, laughing, grabbing her and pulling her down on the bed.

"Mark!"

Lexie stayed over at Mark's that night.

The next day, they walked into the hospital together, hand in hand. They walked down the hallways, through the waiting rooms, past the elevators. Everywhere they turned, someone was giving them a dirty look. They didn't care, well maybe a little, but they're trying to prove a point, no matter how long it takes.

"Ah well isn't it my two little lovebirds," Callie said when she saw them. "So, you told Derek huh?"

"No… he kind of… found… us in the supply closet," Mark replied.

Callie burst out laughing. "I told you guys to be careful! How'd he take it?"

"Not good," Lexie said, "He walked out and we haven't seen him since. Or Meredith."

"Oh well I guess we'll get to find out now," Callie said, looking towards Derek who just entered the room.

"Derek, can we talk about this?" Mark asked as he rushed to catch up with Derek, leaving Lexie and Callie behind.

"Mark, I don't want to hear it."

"Derek, it's your fault! I never thought about Little Grey in that way until you told me not to."

"Okay, and that made it okay for you to sleep with her?"

"No, Derek, it's not like that," he said, trying to keep up. "I, well, I've never felt this way. W-We're happy, Lexie and I."

"Okay," Derek said as he entered his patient's room.

"So, you're okay with this?" Mark asked.

"No, not at all."

"Meredith!" Lexie said when she found her walking down the hallway.

"What, Lexie?" Meredith asked, stopping to turn and face Lexie.

"So, a-a-about what h-happened yesterday in the-the supply closet-"

Meredith didn't let Lexie finish her sentence. "Lexie, you can do whatever you want."

"M-Meredith, I really need you to be okay with this."

"Lexie, he's, like, ten years older than you. And he's a whore, and he broke up Derek's marriage."

"H-He's different w-with me. I don't know what we are, but I've never felt like this before and I really like him."

"You can do whatever you want, Lex, it's not up to me."

"M-Meredith, please!" Lexie said as Meredith walked away.

"So, how'd it go with Derek?" Lexie asked Mark as they sat down to have lunch in the cafeteria.

"Pretty much the same as yesterday. Meredith?" He asked, looking up at Lexie.

"Not good. What are we going to do?"

"Lexie, I don't care what they think. It was worth it."

"N-No it wasn't. Well, maybe a little," she said with a little laugh and a smile.

"They're going to have to get used to us sometime; let's go back to Meredith's," Mark suggested.

"I like the way you think, Dr. Sloan."

"Why do you guys have so many muffins?" Mark asked, laughing.

"Izzie likes to bake. Plus, you can't really complain about having too many muffins. Her problems could be a lot worse." Lexie and Mark both laughed at the multiple overflowing bowls full of muffin all around the kitchen. Lexie leaned in to kiss Mark. He grabbed her waist and set her down on his lap.

"Ahh, come here." She smiled and rested her arms on his shoulders as he kissed her neck. He wrapped his strong arms tighter around her waist, pulling her body closer to him. He moved his mouth lower and lower and then went back up the other side of her neck. Lexie let out a soft moan as he moved back to her lips. Their kiss grew deeper and more passionate until they heard the chatter of Derek and Meredith entering the kitchen. Lexie pulled away quickly and Mark dropped his head in disappointment. Lexie got off his lap, stood up, and walked to the other side of the kitchen where she forcefully stuffed a muffin in her mouth. Derek looked back and forth between the two of them, gave Mark a dirty look, and then walked to a different room without saying a word. Meredith, however, as uncomfortable as this relationship makes her feel, is nowhere near as mad as Derek.

"Lexie," she said, "you might want to slow down a little." Lexie realized she had started to stuff a second muffin into her mouth. "Those are the old ones by the way. Izzie put the new ones in the living room." Lexie grabbed a towel and spit the muffin out. Meredith then turned to Mark. "You might want to leave, Mark," she said.

Mark got up and walked to the door. "No, you know what," he started, "I'm not leaving. I don't care what Derek thinks. I'm with Lexie. She makes me happy, and I think I make her happy too. We're happy, and he should be happy for us."

Meredith raised an eyebrow at Mark, then turned around to find Lexie trying to hide her smile.

"I'm staying," Mark said. Lexie ran up to him and pecked him hard on the lips, wrapping her arms around his neck. They both laughed and he tugged a bit at the waistband of her jeans. She jumped up and wrapped her legs around him. Mark held on tight and headed up the stairs to the attic. As their laughter faded, Derek came back to the kitchen.

"Whew," he said, "are they finally gone?"

"Not exactly," Meredith answered.

Right on cue, there was a loud slam, a door shutting, followed by an outburst of laughter. Derek rolled his eyes, grabbed a muffin, and left the house.

"Thank you," Lexie said, looking up at Mark as he zipped up his pants.

"For what?" he asked, "For that hot, hot sex? Your welcome," he said with a laugh.

"No," she laughed, "for standing up for us."

"I just wanted to have hot, hot sex."

"Get out, you moron," she said, throwing a pillow at him. They both laughed until finally, he opened the door and left to go back the hospital.

Lexie rolled over in the bed onto her back, just thinking about Mark. He had a soft, gentle touch that made him vulnerable. He also had strength and power that could influence her to do anything. She thought about the way he has changed since he's been with her. As far as she knows he has been monogamous to her. Monogamy is against Mark's reputation, he's been known to sleep with multiple women at a time, and he's been known to drop them the next day. Lexie smiled at the fact that he's changed for her. Lexie's thoughts soon drifted from Mark's reputation to his body. She thought of the short stubble that highlighted his sharp jawline. She thought about his strong, broad shoulders that connected to his perfect arms. She thought about the sharpness of his abs. Mark, is perfect.

Mark stormed into the hospital.

"Woah, someone's excited. What happened?" Callie asked, trying to keep up with him.

"Little Grey," he said, "I think I'm going to ask her to move in with me."

"You mean both of you, living across the hall from me?" Callie asked.

"Yeah…"

"It's just," Callie said, "our walls aren't very soundproof."

They both laughed, remembering the times that they've had to cover their ears with pillows or turn the music all the way up because the other was having a little too much fun across the hall.

The next day, Mark nervously waited with two cups of coffee. He was waiting for Lexie to get to get off rounds so he could ask her to move in with him. Mark didn't know why he was shaking. He's never been nervous around a girl before. He was always straight forward, and no one turned him down. Why did Lexie make him nervous? Maybe because she made him feel things he's never felt before. Could he be falling in love? Mark quickly snapped out of his – getting a little too serious – thoughts when he saw Lexie walking towards him. He liked the way she walked, she walked confidently even though she didn't realize it. This makes her even more attractive, she has no idea how beautiful she is.

"Hello, Br. Sloan," she said as she grabbed a coffee out of his hand.

"Dr. Grey," he started, "um, yeah." He took a sip out of his coffee.

"What's wrong?" she asked.

"Um, would you want to come see my apartment?"

"Um, Mark, I've seen your apartment before."

"Oh, uh, yeah, yeah I know. I mean, um…" His voice trailed off. He turned and stood up strong and tall, boosting his confidence. "Do you want to move in with me?"

"Oh! Um, yeah, I guess. I mean, not right now," she answered.

"Well, yeah, I mean, we can wait a little while."

"Yeah, like ten years."

"I'm sorry, what?"

"Well I-I'll still be a resident for like six more years, and then I'd want to get my practice up and running, so, how about seven years?"

"How about five?" He asked.

"I-I'll still be a resident."

"So?" He asked. "Stevens and Karev are residents, Bailey, Meredith, all happily married or soon to be."

Lexie shivered when Mark said 'married'. "Uh, um, I'm sorry, are you asking me t-to marry you?"

"No," he said awkwardly, with a little chuckle. They both laughed for a second. "Why? Would you?" He asked.

"Um, should we be having this conversation?"

"No, no, probably not," he said, widening his eyes. She quickly grabbed her coffee and walked away, sipping nervously. Mark turned around at the sound of laughter. Derek was standing at the other side of the nurse's station. "How much of that did you hear?"

"Oh, just the part where you asked her to move in and she turned you down. I also heard the awkward marriage talk." Mark laughed at himself. "I'm still not okay with this."

"Derek, I give up. If I hadn't fallen for Little Grey, you would have found some other reason not to respect me, you always have. To you, I will always be the charity case the Shepard's had to take in." Derek walked away and Mark decided to check on his patients. He found Lexie stitching up a wound on a woman's forearm.

"There's going to be too much pressure," he said without looking at Lexie, keeping his eyes on the other woman. "Start over and do a layered closure."

"Uh, um, ca-, uh, can I ask a question about that?" Lexie asked.

They both walked to the other side of the ER.

"Why won't you make eye contact with me?" Lexie asked. Mark stayed silent, still watching Lexie's patient. "Okay, y-you brought up marriage and moving in together and I put it off. Now you're embarrassed and won't make eye contact, right?"

"You can go find something else to do, Grey, I'll redo your patient's sutures," he said, still looking away. Lexie looked back at her patient, realizing Mark was eyeing her.

"Fine, Mark. That's real mature of you," Lexie said angrily as she stormed away.

Mark turned and watched Lexie as she walked away. He let out an exhale as if a huge burden had been lifted off his chest and walked over to the patient.

"Hi, I'm Dr. Sloan, head of plastics."

"Oh, it's just a little cut, I don't want to disrupt your schedule."

"It's fine, I wasn't even supposed to come to work today," he said with a smile.

"Well, why did you come?"

"I came to ask Dr. Grey to move in with me. Obviously, that didn't work out."

"How long have you two been together?" She asked.

"Um," Mark was taken aback when he realized he had no idea. "I actually don't know. We had a, um, 'thing', for a while, and that turned into a secret fling. People know now, though, they've got a bit of mixed emotions about us. Our ages and positions here at the hospital." He realized he was being way too open with his patient. "S-Sorry, I shouldn't be telling you all of this."

"No," she said, smiling, "I like listening." He smiled back, realizing she was flirting.

Lexie decided to stop by Mark's apartment after her shift to apologize. She waited as the elevator slowly moved up. Ding. The elevator stopped and the doors opened. Lexie froze when she looked down the hallway. Her throat tightened and she couldn't move. Mouths touching, hands wandering, Mark and Lexie's patient from earlier were undressing in the hall as Mark unlocked his apartment door. She moaned as they went in. Standing there, in shock of what just happened, tears started to fall from Lexie's eyes. She didn't feel like driving, she went and knocked on Callie's door. Right as the door opened Lexie ran in, sobbing.

"Woah!" Callie exclaimed as Lexie almost hit her with the door. "Wait, if you're here, who's making all that noise?"

Lexie looked up at Callie from Callie's couch. Callie went and sat next to her. "What happened?" Callie asked.

"M-Mark asked me to move in with him. I-I-I put it off and he got mad. Now he's over there doing god knows what with his patient." Lexie continued to cry.

"Dammit Mark," Callie mumbled. "He loves you, you know, right?" Callie said, raising her voice.

Lexie laughed. "Yeah right," she said, "I'm just another one of his many sexual partners."

"No, Lexie, he loves you. He won't admit it to himself, but he loves you. You know Mark, he's just hurting and now he's acting out. He'll regret it tomorrow."

Lexie looked up at Callie for a second, then continued to cry. Callie stood up and went to the other room to call Meredith.

"Hey, it's Callie," she said.

"Callie?"

"Yeah, so, um, Lexie is at my place right now, you might want to come get her."

"What's wrong?" Meredith asked.

"You'll see when you get here."

"Oh okay, in another hour Derek and I can come get her. Is that okay?"

"Yeah, see you in an hour." Callie hung up the phone. She went and sat back down next to Lexie. Callie didn't say anything, she knew Lexie needed space.

Meredith and Derek walked down the hall of the apartment building until they got to Callie's door. Callie opened it right away and Meredith rushed to Lexie, still sitting on Callie's couch. Derek and Callie stood in the doorway as Callie explained to him what happened.

"Lex? What's wrong?" Meredith asked. Lexie had stopped crying but her eyes were still puffy and red.

"Mark."

Before Meredith got the chance to ask any more questions, the door across the hall opened. Mark eyes widened in terror when he saw Derek, Callie, Meredith, and Lexie all in Callie's apartment. He noticed that Lexie had been crying.

"Um, I'm going to go," the woman said. Mark payed no attention to her as she walked away, his eyes were fixed on Lexie.

"Oh my-" Mark started.

Derek quickly grabbed Mark's arm and pulled him into his apartment. "What the hell were you thinking?" Derek yelled

"I-I, I don't know," Mark replied, already regretting everything. "Dammit!" He slammed his fist on the wall.

"This is why I told you to stay away from her, Mark," Derek walked back into Callie's apartment. "We should go," he said to Meredith. Derek and Meredith walked Lexie out of Callie's apartment.

"Lex," Mark said. You could hear the disappointment in his voice.

"What, Mark." Lexie replied angrily, pulling away from Meredith's grip.

Mark inhaled like he was about to speak, but nothing came out. Mark had absolutely no way of explaining himself. He knew it was wrong but he still did it.

"Exactly," Lexie said when he didn't respond.

"No, Lex! Can I speak to you, alone?"

"No, you cannot!" Meredith and Derek both said simultaneously.

"No, it's okay," Lexie said.

Lexie walked past Mark, into his apartment. He followed her and closed the door. Meredith, Derek, and Callie waited inside Callie's apartment in silence. They could hear Mark and Lexie yelling from across the hall.

"What?" Lexie asked.

"Lex, there is no explanation for what I did. I was mad that you didn't want to move in with me. It all happened so fast. I was confiding in her about you and me, a-and it just happened."

Lexie could hear the regret in his voice. "Yeah? I just wanted a little time to think!" Lexie raised her voice. "Of course, I wanted to move in with you! I just needed time to think!"

"Lexie, I know I messed up. I can't validate anything I just did. All I know," he paused, "all I know, it that I'm in love with you."

They remained quiet for a second, both surprised at what he just said.

"I, I, um," Lexie started, unable to finish her thought.

Mark took a step closer to her. Lexie could feel the tension, so she stepped back. A few seconds later, Mark walked closer again. This time, Lexie didn't move. Mark slowly brought his hand up to her face and cupped her cheek. Lexie closed her eyes and leaned into his hand. Mark gently placed his lips on hers. At first, Lexie didn't refuse, she let him kiss her. With his other hand, he grabbed Lexie's waist and pulled her closer. Lexie started to kiss back. They made their way to the bedroom. However, as she fell on the bed, she realized what had just happened in this room. Lexie pushed Mark off of her and ran to the door. She turned back to Mark.

"I-I'm sorry. I can't do this, Mark. I'm done." She opened the door and walked out. Meredith and Derek jumped up when Lexie came out. They had kept Callie's door open so they could see what was going on.

"Are you okay?" Meredith asked as they joined Lexie down the hall.

"Yeah, I'm fine," she answered, her voice wavering.

As the three of them entered the elevator, Mark and Callie stood at their apartment doors.

"You're," Callie paused. "You're an idiot."

"I know." He ran both his hands up his face and grabbed his head. "What the hell am I doing?"

A/N - So, that was eventful. Lexie and Mark just had their first major breakup. Sorry to end this chapter on a sad note. Next one should be out in a few days! Let me know what you thunk! Reviews really, really help. Thanks for reading!