I DO NOT own Chicago PD
This is my first crossover prompt, something I have never done before. Just remember that it is a Linstead story, there will be twists here and there. I hope you enjoy this chapter, because I really do. Thanks for all of the reads and the reviews, I do read them!

Chapter 6- We can't

The day for Jay went by in a blur, nothing really memorable; he was just excited to see Erin again. He was nervous to see how they would act around the rest of their coworkers. Erins day was busy compared the rest of her Saturdays, working out, grocery shopping, and the usual checking on Justin. The only memorable thing that happened to her since she left Jays that morning was running into Kelly Severide, literally running into him, at the gym. She was running on the track and looked down at her phone to see what time it was and she hit the person in front of her because she lost track of her speed, little did she know that person was Kelly Severide from Firehouse 51. "Ow, Shit. Are you okay?" Erin asked panting loudly, looking up to see who it was a smile spread across her face. "Oh, its just you Kelly." The redness faded from her face, at least it was someone she knew.

"Just me, detective Lindsay you're lucky you ran into me, I'm such a popular man." He boasted obviously joking. "How are you doing, disregarding the collision we just had?" He laughed as he helped her up.

"I'm great how are you?" She asked, her breathing slowing down as she stood up.

"A little better now that I saw you," Kelly blushed "I mean, I uh… you know its just nice to see a familiar face around the gym sometimes, and your face is nice to see.." He stuttered out.

"Well yours isn't so bad youself," Erin joked, trying to calm him down a little bit, "Will you be at Mollys tonight?" She asked as she ran her fingers through her hair, redoing her ponytail.

"Yeah I'll be there around 8:30, I'm driving with Shay and she always takes a long time to get ready," He smiled and looked down at her, "Oh, here.." He reached up towards her ear and took a strand of hair in between his fingers "You forgot a piece." He gently pushed it behind her ear while the pad of his thumb graced her cheek as she looked up at him.

Erin cleared her throat to try and get out of the trance that was Kelly Severide.

"Well I'm going to keep running, try to stay out of my way this time," Kelly said as he looked down at her dimples. "See ya at mollys."

"Yeah see ya, Kel." She called after him as he turned around to keep jogging. For some reason Erin touched her hand to her face and she felt as though her skin was on fire. He cheeks were flushed and she was still smiling after he made his way down the track. What is my problem? Erin thought to herself, I have feelings for my partner and Kelly Severide, I honestly need to get this sorted out. As Erin made her way to her car after the workout she had gotten a text from Jay saying that he would be there at 7:50. Lets see how this night goes she thought as she got into the shower.

Jay was waiting out front of Erins a few hours later and couldn't wait to see how the night was about to go. He looked up and Erin came walking down the sidewalk, she looked stunning in the most simple clothes, she was donning dark skinny jeans with black combat boots, a burgundy V-cut long sleeve, and a black leather jacket. Strutting her way to Jays car, he couldn't take his eyes off her. Erin got into the car and gave him a smile with a coy hello and put her seatbelt. Something was off, no kiss hello, no conversations really, she was just texting someone the whole ride there. Jay was disappointed; so far the night was not going as planned. As they pulled up to the light Jay glanced out of the corner of his eye towards Erins phone to see who she was texting. He looked to the top of the message screen and saw the name Kelly Severide. He was confused. He then worked up enough courage to ask her who she was talking to, he knew as soon as she looked at him it was a bad idea. "Who are you texting so much over there?" He tried to play it off as a joke.

"Well is it any of your business Halstead?" She asking kind of quizzically, turning her head towards him.

"Just because you've been so quiet, I wanted to know if everything was okay.."

"I'm fine, Jay, you dont always have to know what's going on with me you know. Im just texting Justin." She snapped back at him.

"Oh." He had nothing else to say to her, he knew she was lying.

Jay didn't say anything to Erin the rest of the ride to Mollys. She understood why he was on edge, she didn't treat him like she had been the past few days. Especially after what happened last night, she should have acted differently, she thought to herself. Once Jay pulled into a parking spot at Mollys Erin broke the silence, "Jay I just want to get something clear," her voice shook because she knew what she was about to say was 100% false and she knew it would hurt him, "nothing can come from the last few days, were partners, it wouldn't work and Voight would be livid.." She trailed of as she turned to see his reaction.

"Whatever you say, Lindsay." Was all Jay said as he got out of the car and slammed the door.

Erin sat there for a few seconds trying to process what just happened. I'm lying to myself; she thought to herself, I know this is more than a partnership. I think I just ruined that partnership… As Erin was sitting there she didn't realize the tears that began to well up in her eyes, quickly she composed herself and got out of Jays car. Running into Severide as she walked into the entrance.

"Detective Lindsay, this is the second time you have physically harmed me in one day" He smiled as he held the door open for her following closely behind her.

"Why thank you Lieutenant Severide, quite the gentleman" She smirked with a wink. Why can't I flirt with other guys, it's not like anything can happen with Jay, she thought.

"Well can this gentleman buy you a drink, Erin?" He asked her as they walked towards the back of the bar towards their groups. He placed his large firefighter hand on the small of her back and she let him, knowing that it would piss Jay off, but nothing could happen with him, so it doesn't matter.

As Kelly placed his hand on the small of her back she leaned her body into his, accepting the gesture as he guided them through the crowds of people. The night went by quickly, Kelly introduced Erin to all of his friends that didn't already know her and Erin did the same thing to her coworkers. Soon it seemed everyone had left the bar, Jay and Ruzek were the last ones from the district and Shay was behind the bar with Gabby tending to the last few costumers. Kelly and Erin were in the back of the bar at the last bar top table, sharing stories, laughing at each others jokes, and exchanging glances across the table. The night was coming to a close and Erin had a few too many drinks, Severide decided it was time to take her home.

"Okay Erin, what do you say we take you home now?" Kelly asked Erin as she stumbled to grab her jacket from the chair next to her.

"Just as long as you come inside," She slurred into his ear as she leaned onto his body for support, "because Im not ready for this night to end with you." She smirked as she looked up at his gorgeous eyes.