If I Knew Then
Prompt: If I Knew Then- Lady Antebellum

The first time that I saw you looking like you did.
We were young, we were restless.
Just two clueless kids.
But if I knew then, what I know now,
I'd fall in love.

Derek could still remember the first time he met Emily. Fifteen years ago, he saw her in the park in Chicago. As soon as he saw her, he knew he needed to talk to her. He walked toward her. She saw him and quickly got up and walked away. Derek knew this was going to be difficult.

You're on a bus in Chicago,
Three rows to the left.
You know my heart is reaching for you but we never even met.

Two days later, Derek got on the bus and saw the girl from the park sitting a few feet away. She locked eyes with him and quickly looked out the window. Derek sat next to her, but she continued to look out the window.

At the next stop, she quickly ran off the bus, but Derek followed her. There was just something about her that made him want to follow. Derek yelled for her to stop, but she just walked faster. Finally, he caught up to her.

"Why have you been ignoring me?" He said, walking by her side.

Still, she ignored him and kept walking. "Hello, I'm Derek." He tried. She stopped abruptly and turned to him. "I'm Emily. Now, can you please leave me alone?" She continued walking, and again, Derek followed her. "So, Emily, would you want to maybe go out to dinner or something?"

"No." She said, quickly. She walked away.

On a summer night in August,
Backseat of my car.
Said, "I'm trying to get to know you."
But I took it way too far.

Three weeks later, Derek was driving through the rain at night. He decided to stop at the park until the rain calmed down some. He's shocked when he sees a girl standing in the middle of the park in the storm. He opens the door and walks toward her. He's shocked when he realizes it's Emily, the girl he had met three weeks before.

He has to shout over the rain to speak to her. "Emily, I can drive you home if you need." She nodded and got in the backseat of his car. "Sit back here with me, please." She asked quietly. Derek got into the back, but was confused. First, she completely ignored him and now, she's here, in his car, wanting to talk to him.

Once he closed the door, she said, "Why were you following me three weeks ago?" Derek looked at her and then said, "I wanted to get know you." Emily smiled at him, but didn't say anything. Derek looked at her and then confessed, "I thought you were beautiful and I just had to speak to you." He looked at her and then leaned in to kiss her. She quickly pulled away. She got out of the car and ran. This time, Derek didn't follow.

10 Years Later

It was Emily's second day of working at the BAU. Today was the day she was finally going to meet her team.

xxxxxx

Reid walked into the bullpen and sat at his desk. He saw the new agent at her desk and smiled at her. She waved at him and went back to doing her work.

Emily heard someone else walk in as she was working, but she didn't look up. The person began to tease Reid. Reid got annoyed and said, "Derek, cut it out!" Emily heard him say 'Derek' and froze. She hoped this wasn't who she thought it was. After a few seconds, she looked up and was shocked. She quickly got up and went to the restroom. Derek didn't notice, thankfully.

Hotch called everyone into the conference room because he had an announcement. "We have a new agent. This is Agent Prentiss." Emily walked into the conference room and looked at everyone except Derek.

Derek was so shocked to see her. The last time he saw her was when she ran from his car that night ten years ago.

After everyone introduced themselves and went back to work, Emily and Derek stayed in the room in an awkward silence. Emily refused to look at him. "Emily, look at me," he said, but she refused. "It really is you." He said and she couldn't help but smile. Emily finally looked at him.

"Emily, I'm so sorry about what happened back then. I didn't mean to-" Emily cut him off and said, "Let's just put that behind us, Derek." Derek smiled at her.

But if I knew then, what I know now, I'd fall in love.
Cause love only comes once in a while.
Knocks on your door, throws you a smile,
And takes every breathe.
Leaves every scar, speaks through your soul,
And sings to your heart.

5 Years Later

One day, Emily and Derek decided to talk about what happened. "Derek, I wish I hadn't run away fifteen years ago. I wish I had stayed and seen what would have happened." This shocked Derek and he didn't know what to say.

Emily leant up and gave him and quick kiss. She pulled back and looked down. Derek smiled and lifted her chin so she would look him in the eyes. He leaned down and kissed her. She deepened the kiss by wrapping her arms around his neck and pulling him as close as physically possible. Derek wrapped his arm around her waist. When they broke apart, she said, "Derek, I- I love you."

"I love you, too, Emily." He said, pulling her into another kiss.

If I knew then, what I know now, I'd fall in love.