A/N: Thanks to everyone who has read, reviewed, favorited or followed this story!

Special thanks to jenny crum, samcarter1980, dino-dog83, guest, guest, Lexis4Morganprentiss and Jotchprossi18!

I don't own criminal minds!

Chapter 7: Unknown Chemistry

February 15th 2006

The bullpen was completely empty when JJ walked in. She thought most of the team members were going to be there. She needed several consults from them. The pressure of her job was really getting to her. It was like she had no time left for herself. But somehow, she loved her job. It was who she was. It meant the world to her. And it was even better that the team had become like a family. There were as close as a group could possibly get.

As always the lights in Hotch's office were still on. She saw him leaned over his desk. He had been uptight all day. She knew it probably had something to do with Haley. JJ and Hotch had become close. They could talk to one another without any expectations. It was a real friendship and she treasured it more than anything. But deep down she knew, she had a crush on her older boss. There was nothing about him, she didn't like. Except the fact that he was married and he was about to have a baby in a few months. She wanted to see him happy, but she knew he wasn't most of the times.

She had decided to talk to him. She slowly opened the door to his office. Hotch immediately looked up. He gave her a big smile and her heart melted at the sight of his dimples. ''Hi.'' she greeted happily.

''Hey, JJ.'' he said, rising from his chair. ''What are you still doing here?''

''I guess the same as you.''

''Go home, JJ.'' he suggested. She looked exhausted. ''You look tired.''

She dropped to his leather couch. ''I am. I love this job. I really do, Hotch.'' she started. ''But sometimes it takes over my life and I realize that a job shouldn't be the most important thing. But to me it is.''

''I know what you mean.'' he agreed. ''But I also know that you don't want to wake up one day, realizing it's all you have. Life is about more than a job, JJ.''

''What are you saying to me?''

He sat down next to her. ''I am married, but my marriage is slowly falling apart and I have a baby on the way. I know I'll love the baby with my whole heart. But I regret not being home more often. I know my marriage wouldn't have been falling apart if I would've been there for Haley.''

''You're trying. You can't do more, Hotch.''

Hotch decided to change the subject. He wanted to talk about something other than his messed-up life. ''Are you having relationship trouble?''

JJ grabbed a glass and the scotch from the coffee table. She poured some into the glass. She leaned back in the couch with the glass in her hand. ''You know I'm single.'' she said. She took a zip while Hotch just stared at her.

''Just testing you!'' he teased.

''Sure you were.'' she joked. ''I'm not the best at relationships either. I'm twenty-three and I have only had one serious relationship in my entire life. The rest of my time, I dedicated to this job and college.''

''Well, it wasn't for nothing.'' he began. ''You did so well in the academy, you even got my attention.'' he admitted. ''At first I thought a rookie could never do your job, but you've exceeded all my expectations, JJ.''

''That means a lot coming from you.'' she said, surprised after what he had said.

''It's true. You didn't mess up your life in any way. You should be proud of yourself.''

She sighed deeply before speaking. She handed him the glass of scotch. She leaned forward with her head in her hands. ''I don't know if I can. Maybe I should be proud of myself. But there are so many things I wish would've gone differently.'' she said emotionally, thinking about her sister. Only her family knew. She never told anyone else. It was too hard to talk about or even think about. ''I've always seen the good in people. I just feel like I underestimate people.''

''That's a good thing, JJ.'' he said softly. He saw a tear escape her eye. ''What's going on?''

''Nothing.'' she lied as she wiped away the tear. She had never felt so comfortable in her entire life. He made her open up.

''Come here.'' he said while he leaned forward to take her in his embrace. One arm went around her back while he had his hand in her hair. It was so soft. As he held her, he silently smelled her hair. She smelled like heaven.

JJ pulled away when she felt sparks ignite within her. She couldn't be doing this. He was her boss after all. ''This is silly.'' she murmured.

''JJ.'' he whispered. His hand was slowly tracing from her knee up her leg, all the way to her waist. He held it there while a spark went through his entire body.

JJ jumped up from the couch, getting away from his confusing touch. He could make her do anything. And the sexual tension didn't make it any easier. She needed to leave. But the feel of his hand on her wrist stopped her from leaving. Instead, she turned around, looking into his darkened eyes.

He put one hand on her hip while the other was in her soft blonde hair. He slowly leaned forward, closing the distance between them. And then his lips brushed against hers so gently. It felt like heaven. And when she responded he deepened the kiss with more passion. He ran his tongue across the bottom of her lip and she opened her mouth. Their tongues began to explore their mouths as he backed her up against the wall. He covered her body with his own, pressing her against the wall.

JJ's entire world seemed to fade away. It was that thing, that moment she had been looking for. She knew this was it. It was everything she always wanted a first kiss to be. He was rough and demanding and at the same gentle and sensual. She knew he wanted more, but she didn't know if he would regret this when they stopped.

His entire body was on a high he had never felt before. It didn't feel wrong when it really was. He never wanted to let this moment pass by, knowing it would. And that they would go back to being Jennifer Jareau and Aaron Hotchner. Subordinate and boss. Agents for the FBI. But he wasn't going to stop until she wanted to. Their hands were running all over each other's bodies. He carefully lifted her shirt over her head. It fell to the ground.

JJ finally decided to pull away from him when she was standing, half-naked in his office. She quickly grabbed the shirt and put it back on. ''What does this mean?'' she asked bluntly.

''I think you already know.'' he said with a serious face. ''You know JJ.''

''No, I don't.'' she said. ''I don't know.''

A silence fell. Hotch kept staring at JJ as she had her eyes on the floor. She was already avoiding him. But it wasn't for long before she returned his gaze. ''All I know is that you're my best friend. I don't want to lose you because of something stupid.''

''This is far from stupid, JJ.''

''You're my boss!'' she stated.

''So?''

''You're married!'' she added.

''You're having a baby!'' she added as well.

''Okay, stop!'' he said. ''I know all of that. But why does this feel so good?''

JJ stepped backwards. Distance would be the best thing. She knew she couldn't keep her hands off of him if he was to close. ''I don't know.''

''I guess you don't know anything.'' he said bluntly. He didn't want to hurt her feelings, but this situation was uncomfortable for him as well. ''I'm sorry. This isn't easy for me.''

''Maybe we should forget this even happened.''

''I don't want to forget.''

She turned around, storming out of his office. She couldn't do it. It wasn't right. She had always hated the women who had affairs with other men, and now she was becoming one of those girls. Falling for a man who was strictly off limits to her.

She got to her office and quickly put on her coat. She grabbed her bag on the way out, but the door was blocked by Hotch. She could've expected it. He probably wasn't letting her go until they talked about it. He was like that.

''Let me go!'' she pleaded. But he only stepped closer. ''I can't be that girl, Hotch. I can't…I can't.'' she whispered.

He trapped JJ between her desk and his arms. ''I'm not asking you to be that girl.'' he whispered against the column of her neck. He felt her shiver under his touch.

It was that exact moment that JJ gave in. She let her guard down, trusting him with her heart. She trusted him. ''Don't hurt me, okay?''

''Never.'' he replied. He pulled her closer by the belt on her coat. He slowly unbuttoned her coat and let it slip of her shoulders and onto the ground. He leaned in and captured her lips afterwards. It was a fight for dominance. But it was so right.

As the night went on they realized how real their feelings actually were. It wasn't a one night stand. It was the promise of a better future. But as JJ lay naked in the arms of the man she was falling in love with, she knew there were obstacles. And she didn't know if they could ever overcome those. But in that moment she learned to be happy with the moment because she was in the arms of someone who showed her what real love could be like. And that was all she needed to fall asleep.