Disclaimer: Chicago P.D., its characters and universe belong to Dick Wolf and Matt Olmstead and NBC. I'm only a fan, writing this for love of this TV show and personal pleasure.

A.N.: Sort of a companion piece to It's the Adrenaline. I really like Hailey, I think she's one of the best characters of PD and I like getting inside her head. The idea for this came after 6x04.

The Thing About Secrets

Hailey hates liars.

Yeah, she knows it's a bit hypocritical given her line of work and the fact that she spent one year undercover on the job, besides countless other UC stints she's participated in during her ongoing career with the CPD. But there were lies and then there were lies. Lying on the job was something she could justify; she was doing it for the greater good, there were people's lives on the line, they were trying to stop criminals from causing harm.

Now lying about her personal life… That was another matter altogether. Granted, she had always been more of a private person. Maybe it was a personality thing, maybe it was something that came with the job. Maybe it was something to do with growing up with an abusive father who'd beat the crap out of her every now and then and how she'd learned to cover up injuries and bruises from prying eyes. Bottom line was she quickly learned it wasn't exactly wise to advertise details about your life out there unnecessarily. People could take advantage of such knowledge and use it against you, from stealing your identity to commit crimes to sweeping that promotion you'd worked so hard for right from under you to even more dangerous situations like rape or murder.

So lying by omission wasn't exactly as bad as straight up making up lies just for the heck of it. And again, she knew it was something about human nature. People lied about all sorts of things, for the most various reasons. Self-preservation, pride, fear, to maintain an image, to protect someone, or then just for the heck of it. The list went on and on.

And then there was something about secrets. There were secrets that weighed in your heart, like the one she shared with Voight on the truth concerning the death of McGrady, so she tried not to think about it. She'd made peace with it (she kept telling herself that, whenever she thought about it) and it was done.

Now this other secret, this thing with Adam, whatever it was that they were doing, she had to admit he was right: it was fun. He was funny, sexy and damn, the sex was hot. They liked each other and they got along but it wasn't like they were in love or anything. It had started mostly as an aftereffect of her getting drunk (after almost losing Jay) and then falling into bed with Adam. Then afterwards… Well, once you scratch an itch, you kind of want to keep scratching it, you know? And he'd been right, there was nothing stopping them from keeping it up, having some fun and seeing where it was going.

And strictly speaking there wasn't any reason why they should keep it a secret. She'd heard how Voight used to have a no confraternization rule, but that had been thrown out the window after Adam and Kim's relationship, and then with Jay and Erin. Nowadays the sergeant in charge of the Intelligence Unit didn't seem to care what they did with their lives as long as they did their jobs.

Personally she'd agreed with his former rule, and she'd been telling the truth when she told Jay she didn't date coworkers. Things always got messy when you mixed your personal life with your work. Of course, it was rather difficult to separate them completely. She liked hanging out with her coworkers and it was also a nice way of strengthening the bonds with those who put their lives on the line and had her back every day. But then she saw how complicated things had been between Jay and Erin when she'd first joined the unit. Breaking up was always hard, and then having to see your ex every day and work with them? She had no idea how they'd managed to do that for months without blowing up at each other all the time.

It also made things infinitely more difficult when you lost a partner. It was always heartbreaking when a fellow cop lost their lives on the line, but losing someone you were in love with on top of that? She imagined there wasn't something quite as heartbreaking as that.

But that wasn't the case with Adam, there was no complication. No, this was just something they did together now. Sort of like an after work, blowing up steam, exercising sort of thing. She went to the shooting range with Jay, running with Kim, to the boxing gym with Antonio and now she had sex with Adam. Simple as that (or she'd keep telling herself that). And it was nobody's goddamn business.

And yet she'd felt guilty that morning she was late to meet Jay and when he asked what had happened and if everything was okay. She didn't elaborate on her reasons for being late, only deflected his questions by assuring him everything was okay and it wouldn't happen again. She tried to argue with herself that at least she hadn't lied to him, not technically. Everything was okay and from then on she did make sure she wasn't late to meet him again. But just thinking about telling Jay that she was sleeping with Adam? Uh-uh, that was not something she liked to think about. And she also didn't want to think about why she felt that way.

There was another reason why she wanted to keep this thing a secret━other than it was hot, it was no one's business and she particularly didn't want Jay to know. She also had no idea how Kim would react to it. Adam had recently told her his side of the story, but truthfully Hailey and Kim had already talked about it over the past year as they became closer friends and shared some things with each other. And Kim had told her it was something that was in the past and how she didn't see a future with Adam. She'd had other relationships since him and she didn't seem to spare him another thought to what he did with his life. But Hailey had a nagging feeling in the back of her mind that if Kim actually saw him "moving on" and having a life after her the reality would really hit her, maybe harder than she'd expect.

So now here she was, living this secret and so thoroughly enjoying it, while at same time feeling guilty as hell and hating herself for lying. She tried to cool it down somewhat, cutting Adam off when he suggested going to her place yet again. He'd boldly been teasing her and leaning into a kiss, but they stopped themselves when the door to the locker room got open and someone walked in. Hailey cringed inside when she saw it was Kim, but years working undercover had taught her well to hide her reactions. But when the brunette had looked over the two of them, Hailey had caught with the corner of her eye how a question mark seemed to light up in her eyes.

She'd intended to cool things off, she really had. After all, even if they weren't exactly completely in love with each other they were human and if they kept seeing each other, if they kept getting involved then… Things could get a lot more complicated. And she wasn't eager to get to that part, so she'd been intent to put something distance between them. But then they'd had that difficult case with Adam's dad and she'd wanted to be there for him and they just couldn't stop seeing each other.

It was nice, having someone to get into bed with almost every night and to wake up to in the morning for a hot cup of coffee. Someone to laugh, kiss, cry and hold tight when things got too heavy. Someone to share the darkest parts of her life with and that wouldn't judge her and that could just listen and be with her. She'd forgotten what that was like, she'd gotten used to being alone for so long now.

But she wasn't ready to share this with anyone else, letting other people in on this secret with Adam. She wanted to stay in the bubble for a little longer. She hadn't planned on any of this, but things were happening regardless of her wishes and wants. Yet she could feel their clock was running of out time and sooner or later people would be in the know.

That was another thing about secrets. They never lasted long, especially when you worked in the Police force in the Intelligence Unit. And usually when secrets came out someone was bound to get hurt.

A.N.: It goes without saying━yet I'm going to say it━no slut-shaming, please. I like my women to be confident and sexually empowered, and Hailey Upton is all that.

I can't wait to see how more people finding out about Upzek is going to go. I'd really like to be right that Hailey's motivation for first sleeping with Adam would be feelings she actually has for Jay (which could create a lovely love triangle) and I'm not sold on this pairing they're selling us of Hailey and Adam (to me they're kind of like Choi/April on Med or the beginnings of Stellaride on Fire, completely out of left field), but I'll keep an open mind and see where this goes with the coming episodes. The developments in 6x06 almost put me off finishing writing and posting this, but I thought, what the heck? Maybe other people might like this.