Hey everyone, so this is my first fanfic so I would really love it if you would review it. This is an AU, so Mouse's name is Josh instead of Greg and Jay has a little sister, who is 6 years younger.I'm really sorry about the spelling/grammar mistakes. Please enjoy.

Disclaimer: I don't own Chicago PD or its characters.

Chapter one:

Erin's POV

I woke up to the sound of the coffee machine working. Laying in bed for a few more minutes looking out the window at the view of Lake Michigan. The way the sun shines through the room is a completely different angle then my apartment. Reaching to my right, all I can feel is cold sheets. My boyfriend has probably been up long before me.

My boyfriend. God, I love saying that.

"Good morning" I'm pulled from my daydream when Jay brings my a warm cup of coffee and a plate of choc chip pancakes. My favourite.

"Mmmm. Morning" I mumble as he kissed my lips.

"What are you thinking about?" He says as he sits down to my right, holding his own cup of coffee.

"That I could really get use to waking up like this" I grin down at him as I straddle his waist while his hands come up to hold my hips.

"Shouldn't you be getting ready for school?" Jay asked referring to my last semester of university.

"I've got no lectures today, so I invited Maddie over to study with me". I whisper against his lips.

"I still can't believe you trust my little sister enough to keep our secret" He smirks up at me before kissing me.

"I didn't mean for her to find out. It's not my fault you gave her a spare key to your apartment" Remembering how Maddie walked in on us making out like two teenagers. And her saying that she would be scarred for life.

"You know if Maddie knows then it's just a matter of time until he finds out" The serious look on his face tells me he isn't messing around.

"Jay... he won't" I sigh.

"You've been saying that you'll talk to your dad about us for ages now. Yet here we are, still secretly dating".

"My dad always been overprotective, if he ever found out I was sleeping with one of his detectives, who is 4 years older than me, he would be livid" I try to convince Jay.

"But you know that even before you showed up to my doorstep that night" He says.

I'm sitting in his lap, thinking about that night. The first time he kissed, the first time he made me orgasm harder than any other guy. Ever.

"Just give my a couple days, a week at most and I will tell my dad about us. I promise" I mummer as I lean down to attach our lips together.

He gives in and flips us so he's on top, kissing down my neck. The coffee and pancakes long forgotten about.

—Linebreak—

After Jay kissed my goodbye, he left for work.

20 minutes later, there was a knock at the door. Walking to the door, I smile at the sight of my boyfriend's sister, carrying more books then she can handle.

I take a couple of books from her and place them on the coffee table in the living room.

"Hey Maddie, you want some coffee or hot chocolate? Or maybe some leftover pancakes?" I say to her as I walk towards the kitchen.

"A hot chocolate would be great, thanks." As I hand her a already made cup of hot chocolate. She's my best friend, of course I know she is going to want a hot chocolate.

"So, how are you and my brother?" Maddie asks. She is literally the only person I can talk too about Jay and I.

"I guess we are going fine. But Jay wants me to tell my about us and I'm scared that dad will kick him out of Intelligence, I don't know what to say" I answer truthfully.

"Just tell him the truth, you and Jay have been secretly dating for the last 3 months because you were scared that he will kick Jay out of the unit". She says with her mouth full of hot chocolate.

"Yeah, 'cause that's not going to be hard to say" I reply sarcastically.

"Hey, you asked me for my advice and I gave it" She says defending herself.

"Yeah, I'm sorry. I'm just on edge about this. But no more talking about this, let's start studying." I say while pushing her out of the kitchen towards the living room.

After about 4 hours of studying, I suggest that we order pizza for lunch. I order the pizza and 20 minutes later the pizza arrives. I pay the guy and walk back to the living room.

As I put the pizza on the table, the receipt falls to the floor and Maddie picks it up.

"Awww. Someone's got an admirer" She says as she shows me the back of the paper, showcasing a guy's name and his phone number.

"Well, I've got a boyfriend that I'm happy with". I say with a grin in my face.

We spend the next couple of hours studying. Me on law to become and lawyer and Maddie was already a firefighter at Firehouse 51 but she was studying to become a paramedic as well. She says if she has the skills of both, then her resume would be better.

I always tease Jay about his family. His older brother is a doctor due to his father's request. Jay, the middle child, a former army ranger and Chicago detective. And finally Maddie, the firefighter and almost paramedic. Their family has a similar liking in danger.

When it became dark, Maddie said she had to get home to Josh, her boyfriend and Jay's best friend from the army and now he works a tech specialist in Intelligence. Everyone calls him 'Mouse' because when he was in the army , he was 'as quiet as a mouse'. Maddie says she refuses to call him Mouse and calls him Josh.

I knew Jay was working late tonight, he was working overtime do he could pay off his apartment faster. So when I hear a knock at the door, I immediately freeze. This is Jay's apartment and being a cop you make a lot of enemies. I knew from when I was little my dad always had to double check the locks and the windows before going to bed.

I slowly walk to the door, I knew how to throw a solid punch and how to shoot a gun because my dad would always take me to the shooting range, against my mother's wishes but when she witnessed how happy I was when I got to spend time with dad so she allowed it.

I look through the little peep hole and I saw someone I never thought would know in this door.