This is a tag to episode 3.13. I've always thought the Linstead undercover scene needed a little more and I finally got around to writing it. Just a one shot so I hope you enjoy :)

*Italics are straight from the episode*

I don't own CPD or characters.

"Hey! Where you going?"

"The city. I wanna spend some of this."

"You're gonna drive?! How many whiskeys you have?! Seven?!"

"Oh! Now you're counting?!"

"Yea. When I deal with a drunk I count drinks," he said as if it was the most obvious thing in the world.

She reached up and slapped him hard. She let her anger get the best of her as his words echoed in her mind on repeat. His face said it all. Shock she'd actually slapped him, annoyance everyone had saw, and the resignation and guilt at what he'd actually said sunk in.

"Find someone else that needs saving," she said walking off.

"You know what?! Knock yourself out," he tossed back clearly pissed.

She knew they were undercover and it was part of the act to get her to leave without him, but his words had still hurt and she'd reacted.

Jay watched her leave feeling like a complete ass. He hadn't thought before he spoke. They were just playing the part and in the fight it just slipped out, but he knew his words had cut her deep.

"Halstead, let's roll," Atwater said in his ear wig. Jay shook himself out of his daze and raced to the car knowing he needed to get it in gear to back Erin up.

He suited up as they followed as planned. When they pulled up, he made sure to keep it professional. He didn't dare not, knowing she'd explode if he did. Once Atwater had the guy in cuffs he took her his jacket knowing she had to be freezing.

When she wrapped it tighter around her, he knew she wasn't totally pissed at him. They didn't discuss their fight the rest of the shift. It bugged him to no end too, but they wouldn't dare break the professionalism and give Hank a reason to bitch at them. Tonight he kept telling himself.

That night though, Erin claimed she was too tired and just wanted to go home and to bed. Jay didn't push it, knowing how she liked her space. He didn't sleep though. He tossed and turned all night replaying the fight over and over.

His words, slipped out by accident in the heat of the moment, haunted him. He started to text her or call her half a dozen times during the night but he didn't want to wake her. He didn't know she wasn't sleeping either.

The fight also played on repeat in her mind. She knew she should've at least apologized for the slap, instead she'd done what she does best and pushed him away. She knew they should've talked about it and she started to call him and say as much during the night but she didn't want to bother him.

The next morning they were both left with a whole bunch of should'ves and could'ves, and very little sleep. Jay prayed it was an easy day and Voight stayed off their case because he really wasn't in the mood.

He still stopped and got her coffee, and since he didn't sleep any, he was in early. He left it on her desk and got started on paperwork. Erin was the last to arrive and she saw the coffee waiting on her desk.

She instantly felt more guilty knowing she should've talked to him. He offered her a small smile seeing she'd made it and then went back to paperwork.

Erin sat down at her desk with a sigh. They really needed to have a talk but it didn't look like that was going to be happening soon.

They were stuck at the district all day doing paperwork and odds and ends. Erin was really getting frustrated with the lack of conversation between her and her partner/boyfriend, and while she knew it was mainly her fault, she needed to talk to him.

Finally toward quitting time, she sent him a text asking if he wanted to come over after shift. He quickly replied with yes and that made her feel a little better. At least he wasn't totally mad at her.

Jay was relieved to get Erin's text. He was already tired of the space and it hadn't even been that long. While he respected what she needed, she also needed to hear what he had to say.

Jay stopped and got beer and pizza on his way to her place. He thought of every possible way to apologize on the way over. By the time he knocked on her door, he knew just what he needed to say to her.

"Hey," she said quietly with a small smile letting him in.

"Hey. I got pizza and beer," he said heading for the kitchen.

Erin bit her tongue holding in her smart ass reply about drunks and beer. She was going to apologize not make things worse.

"Great. Jay listen,"

"No Erin wait. I gotta tell you something first." All of Erin's fears slipped into her mind knowing she'd probably ruined the best thing ever with a simple undercover sting.

"Stop it," he whispered reaching and pulling her close cradling her cheek. He could see the fear and doubts in her eyes thinking she'd ruined things, when he was the one that had messed up.

"Jay…."

"No Erin. Let me speak," he said waiting until she nodded her agreement.

"I'm sorry. I didn't mean what I said yesterday. I wasn't thinking. It just slipped out in the heat of the moment. All I thought was that it fit good with the fight and scene so I said it. I wasn't thinking and I didn't mean it toward you in any way. I really am sorry."

"I know," she whispered looking down. Jay was quiet. He hadn't been expecting her to say that. He'd been expecting a heated discussion trying to explain his comments and actions and them eventually agreeing to disagree. But she'd just admitted she knew he didn't mean it and that gave him all the hope in the world.

"You do?" he asked rubbing her cheek and making her look at him again.

She nodded. "I didn't sleep last night. I couldn't. It kept playing over in my mind and I wanted to call you many times and apologize but I couldn't bring myself to bother you. I never should've slapped you Jay and I'm sorry," she said leaning up on tip toe to kiss his cheek where she'd hit him.

"I deserved it," he said kissing her forehead.

Erin gave him a small smile. "Maybe a little, but I was never mad. Hurt a little but not mad."

"I know," he whispered. "I really am sorry."

"I know you are," she smiled standing on tip toe once more to kiss him on the lips.

"Let's just forget it. We were undercover playing a role, and it's not gonna effect us any longer."

Jay smiled. "I'll agree to that," he said sealing the deal with a kiss. They ate dinner and watched the game together.

"Erin," he whispered into her head as the game came to an end.

"Yea?" she said looking up at him.

"You'd never bother me. Anytime, day or night I'm always here for you. Just call."

Erin gave him her signature smile. "I know," she said leaning up and kissing him.

They cleaned up from dinner and curled up in bed totally exhausted from the day and fell sound asleep wrapped in each other's arms.

Hope you enjoyed. If you have any other linstead ideas or episode scenes that needed something more send them my way. I'm trying to get back into writing Linstead and Manstead so maybe I can finish my multi-chapters I have going. Not making promises but I'm trying and this is a start :)