A/N: The first part of this story take place in high school. There will be a time jump in Chapter 3.

Chapter 1

They laid in bed together. Just like they always did. The past two months they've been seeing each other. There's always been this attraction they both have had for one another. They didn't dare to act on it until one night they finally did.

Mark placed soft kisses along Lexie's shoulder as she let out soft moans. She knew what he was doing. Trying to ease his way into another round. "Babe, we can't go again... My parents or Meredith will be home soon." She said softly, trying to protest, but her body leaned into him wanting more. "So, we do a quickie." He replied with a smirk against his lips. She blushed at his expression, remembering how quick he can actually be.

Their heads turned when they heard the front door close from downstairs. When Lexie didn't hear either of her parents voices call out, she knew it had to be Meredith. "I thought you said we had time." Mark huffed as Lexie quickly pushed him off of her. "I guess someone's plans changed." She replied as she quickly put on her sweat pants and loose t-shirt. "Hide in the closet." She told him as she picked up his clothes and shoes. Mark just smirked as Lexie was panicking. "Go." She huffed as she guided him towards the closet.

"Lexie, you home?" Meredith's voice called out as she approached her door, knocking on it before walking in a few seconds later. "Yeah." She turned to her half sister quickly as she shut her closet doors. "Just cleaning up my room a bit. How was your night?" She asked her, changing the conversation away from her. After a few minutes of talking with Meredith, she finally got her to leave her room. "Okay, you can come out now." She whispered loud enough for Mark to hear. "It's about time." He said as he opened the doors and began to put his clothes back on. "It was getting hot in there." He grinned. Once his clothes were back on, he walked over to Lexie. "So, I'll see you tomorrow? We can go somewhere after school." She nodded. "Of course." She smiled before kissing him.

A week had gone by and it was now Friday night. Lexie had agreed to go to Alex Karev's party tonight, thanks to a very persuasive best friend. Izzie had talked her into it even though she wanted to spend time with Mark. But she figured he was probably going anyways and maybe they could sneak away together later. She had just finished applying her makeup when she received a text from Izzie saying she was here. Lexie quickly grabbed her things and went out the door.

"Damn, you look hot!" Izzie chirped as Lexie got in the car. "Who for? Your secret boyfriend you never talk about?" The blonde teased as she began to drive. Lexie hadn't told anyone about her and Mark. Not even her best friend. All Izzie knew was that there was someone she was talking too.

Once they arrived and got into the house, the party had already been flooded with people. Which they figured. It's Alex Karev's party. The two met up with their friend Cristina. When they greeted each other Lexie offered to get drinks. And with that she made her way to the kitchen. Just like she expected, she spotted the familiar face she wanted. "Hey, there." She said. "Hey, I didn't know you were going to be here." Mark spoke as he turned to face her. "Yeah, well, Izzie talked me into it." She chuckled. "Well, I'm glad she did." Mark said as he sneaked a kiss on her lips. As much as Lexie wanted the kiss to last longer, she pulled away. "You know we can't. What if someone sees us?" She looked up at him. "I know." He whined. "But you're irresistible." He told her seductively, his hands running down her body. "Come with me." Mark then grabbed her hand and lead her upstairs.

Once upstairs, they ended up in the bathroom. Mark propped Lexie up on the counter after shutting the door. "Wow, I guess I am irresistible." Lexie commented chuckling as Mark began kissing her neck. "Mhm." Is all he said as he continued. She pulled his head up to kiss her lips. Their hot and heavy kisses were soon interrupted when someone opened the door. Damn it. Mark thought to himself. Should've locked the door.

When they both turned to see who it was. They both were in for a shock. "What the hell." Derek cursed, his anger rising quickly. "Unbelievable." He spat and turned around before he could do anything he'd regret. "Derek, wait!" Mark called after him. But he kept walking. "Derek!" He called again and caught up to him, placing his hand on his friends shoulder, once they were downstairs. "Do not touch me." Derek shouted as he swatted Mark's hand away. The commotion between the two brought attention to them and people began to stare. "Come on, Derek." Mark scoffed. "You're being a bit over dramatic." He added. "I'm being over dramatic? I told you to stay away from her!" Derek shouted, shoving his friend back. But Mark didn't step down, he shoved back but didn't expect Derek to come back with his fist clashing to Mark's face. Derek adding another swing, knocking Mark back, before getting pulled off by some guys at the party. Lexie gasped as she watched from the distance. As Derek left, with Meredith at his side, she saw Mark head to the kitchen. She quickly followed him.

"Mark." She hollered, entering the kitchen. "Are you okay?" She rushed up to him, lifting his head to get a clear view of his face. "I just got punched in the face. What do you think?" Mark snapped. His anger at a rise. "We knew this would happen." Mark shook his head. "We should've never..." He trailed off. Lexie was taken back by his attitude. So, this is how he was going to act now. Take his anger out on her. She scoffed. "Screw you, Mark." She spat before walking out.