My sporadic writing is getting at a new high i'm afraid. I have an annoying habit of starting several prompts and leaving them all unfinished for weeks. However, i'm slowly getting round to them so please be patient with me.

Not too happy with this one, but I have a few slightly better ones coming up!

Thanks to EmilyMay93 for this prompt! I hope you enjoy!

"Did you enjoy yourself last night?"

His head was thumping like crazy, beating like a relentless drum. With each pulsing of his brain, Jay winced and squeezed his eyes shut tighter.

How much did I drink?

His eyes gradually opened. Lightness swarmed behind his retinas and his head pounded. With all the strength Jay could muster, he heaved his body up into a sitting position, cradling his head in his hands for a few seconds before taking in his surroundings.

It didn't all send a surge of remembrance through his mind, but it wasn't totally foreign either. Jay vaguely recognised the room; the position of the wardrobe, the colour of the duvet, the texture of the carpet. He considered the possibility he'd rekindled with a previous one-night stand, and cursed at the thought. They were called one-night's for a reason. He didn't want to complicate things.

He swayed with nausea and swallowed anything rising in his throat. Every movement felt strained and lethargic. Jay didn't know the time, but was pretty sure he'd overslept for work. And he wasn't too intent on getting yelled at by Voight with this kind of hangover.

It was when he swung his legs over the bed that he realised what little clothing he had on. He felt around and sighed a breath of relief when he felt his boxers, though barely on him. At least he was semi covered - there was nothing worse than walking into a girl's living room, unaware of who she is or how you met, stark naked.

His feet hit the floor and he steadied himself for a few more seconds, running his fingers through his bed-head. As he got to his feet, Jay looked briefly around the room, seeking out his clothes. The room was almost neurotically neat, not an item out of place. Sadly, Halstead failed to see any items belonging to him, and had to pray to god they were somewhere locatable in the apartment.

As he creaked open the bedroom door and padded his way down the hallway, Jay felt things coming back to him.

He'd been in this apartment.

Recently.

He recognised that painting. - The panelled floor too.

And then it hit him.

Lindsay's apartment.

He was standing in her living room, in front of the couch.

"Hey." He looked up, hearing the amused tone of his partner. She was standing in the kitchen, fully dressed, with a bowl of cereal in her hands. She looked great, unlike Halstead who felt as though his brain was about to cave inwards. His mind was still bubbling with questions, most importantly, why he was standing in Erin's apartment with nothing but a pair of boxers on while she was chewing with delight on cheerios.

"Did you enjoy yourself last night?"

His mouth went dry. She was still smirking, but he couldn't bring himself to crack his frozen stature. He took a long gulp and subconscious crossed his arms over his chest, feeling too exposed. "Did we..." He gulped again, his mind racing.

"Have sex?" Erin finished for him, taking another spoonful of cereal. "Yeah."

Jay went light headed for a second, steadying himself on the arm of the sofa. His headache had definitely worsened, too. Thankfully, a temporary wave of nausea passed and Jay managed to remain upright. He scowered his brain, pretty sure he'd remember having sex with Erin Lindsay.

What caught him most of guard, though, was her entirely casual tone.

"And you're... Okay with this?"

Not that Jay hadn't ever thought about it, because he had. A lot. But he always got the impression it was never an interest for Erin. At least, not enough of an interest for her to defy Voight and let anything happen between the two detectives. And yet there she was, chomping on cheerios, acting like nothing serious had happened.

"Sure," She replied in a nonchalant tone, dropping her bowl into the sink and making her way over to a nearly naked Jay. "It's just sex, right?"

She was smirking again, and he was waiting for the punchline. But she was adamant, and with hands on her hips, was ready to move past the entire incident.

"We're gonna be late. Hurry up and get ready, we're leaving in ten."

The prospect of work sounded painful. And all he wanted was to curl up on the couch with plenty of sleeping pills and the safe knowledge that he was miles from Voight's gravelly voice.

But Lindsay was running a tight ship, and Jay knew ten meant ten. And he had to find out details from the night before, even if it killed him.

"Hey," He caught her attention before she slipped past him and back into her bedroom. "Have you seen..."

He was suddenly very aware of how exposed he was. It didn't help when Erin's eyes trailed up and down his body with a bemused look on her face.

"Back of the couch." She replied with a painfully repressed grin, before leaving her partner's presence and heading to her bedroom.

True to her word, Halstead found his clothes draped over the other side of the couch and managed to dress himself with great speed. As he pulled his shirt over his head, Jay couldn't help but feel at a total loss for what had happened the night before. The only conceivable way he was going to learn what happened, was to piece together details from Lindsay.

"Coffee?"

Jay groaned with relief. "You read my mind."

She pulled up into a parking spot and the two practically jumped from the car, desperately craving a caffeine fix. They normally just drank at the precinct, disgusting as the coffee there was. But today they were both craving something a little better.

As the entered the buzzing coffee shop on the corner, Jay couldn't ignore the questions crowding in his mind.

"So, last night..." He started slowly, feeling Erin close beside him. "We really..."

He could feel himself blushing. He blamed it on the hangover.

"Yeah," Lindsay replied immediately, stepping ahead of him and placing both their orders at the counter. Jay noted how his coffee order rolled right off her tongue, and told himself not to read into it. "Twice." She added with a hooked eyebrow as she turned back to him.

"Twice?"

It was bad enough for him to have no recollection of one sexual encounter with Erin last night, let alone two. He couldn't even begin to fathom how wasted he was.

She handed the cash over the counter and scooped up their two coffees, handing Jay his as they both headed for the door.

"And was it... I mean, for you, did you find it..."

Lindsay slowed her stride and turned to look Halstead up and down, that signature smirk finding its way back to her lips.

"Decent."

"Decent?" He blurted out, following her out of the coffee house and back towards her car. "Just decent?!"

"It was fun," She continued, rounding the hood of her car while Jay opened the passenger side door. "I mean, you probably had a better time than I did. Pretty sure you called me 'the best you ever had'."

There was a glint in her eye as she slid into the driver's seat, leaving Jay dumbfounded and speechless.

On their way to the precinct, Erin hadn't said much.

They were drunk. Jay kissed her. She liked it. She kissed him back. They had sex. They had sex again. They fell asleep.

Halstead's brow raised quizzically the entire time she told him a vague recalling of the events. He had to admit, he was pretty goddamn angry at himself for not sobering up enough to have it in his memory. Because it sounded like a pretty great night.

Once arriving at work, the two were virtually split apart. Voight wanted Lindsay by his side for the day, and Jay got Antonio.

A fairly intricate drug ring case wasn't all too foreign to the detectives at the 21st, who dealt with that kind of thing on a regular basis. But Jay's head wasn't in it. He wasn't on his game, and even Dawson noticed, telling him to 'get it together, dumbass', on more than one occasion.

But he couldn't get Erin Lindsay out of his head.

She walked past and his eyes followed. She sat on the edge of his desk, like she'd done a million times, and he ached to touch her. She looked at him from across the room and his entire being burned.

And it killed him that he couldn't remember.

By the end of the day, his headache barely subsided.

He felt as though he'd become so used to the pounding in his mind that he wanted to slam his own head on his desk just to try and end it all. Thankfully, before he got to that, Lindsay brushed past his desk and headed toward the break room. And he finally had his chance.

Dawson had left early and Jay was pretty sure Ruzek was shacking up in some empty interrogation room with Burgess. Al occupied his usual corner in the office and Atwater was logging video footage. Perhaps most importantly, Voight was on a personal errand.

Jay followed the lingering smell of perfume and entered the break room, shutting the door behind him. Lindsay looked up from her coffee and smiled at him.

"Hey," She offered softly, wordlessly grabbing another mug to pour him a hot beverage.

"Hey," He gulped, a little too loudly. "So... I think we should maybe talk about last night..."

"Okay, shoot."

"Well..." He was still by the door, stepping only an inch closer. "I've gotta say, when I imagined this happening... This wasn't the reaction I thought you'd have."

"Meaning?"

"Why aren't you freaking out?" He asked. "This is... Big. Aren't you concerned at all?!"

She flicked a gaze momentarily to him, before bringing her attention back to the to mugs before her. She poured without a word.

"We have 'decent' sex, and you're totally fine with it?" He continued, his voice becoming louder. "No worry that we've wrecked our friendship whatsoever?"

Erin took a sip of her coffee and the silence was beginning to irate Jay.

"Will you give me something here? I can't remember a thing, and-"

"You showed up at my place drunk." Erin started, interrupting her partner's rambling and bringing him to a silence. "It was late, I said you could crash. You were having a rough night and my couch is super uncomfortable, so I said you could have the bed. You made an inappropriate joke, we laughed, you passed out and I had to deal with your restless snoring all night."

He retained the information as she relayed it, somewhat stunned by the time she'd finished.

"So we didn't have sex?" His face creased with confusion, until it dawned on him. "You were messing with me?"

A smile unfolded across the corners of her lips and Jay crossed his arms on his chest, willing himself not to break out in a laugh.

"Couldn't resist." She retorted.

Halstead ran his tongue along his lip as he took in her grin, feeling a somewhat wave of relief at what she'd told him. There was something fairly agonising about not being able to remember his first time with Erin Lindsay. And he was relieved to have not missed the opportunity.

"I can't believe you." Jay stated, watching as Erin came closer.

She slowed as she neared him, pulled into his magnetism. Her eyes flickered upwards, painfully slowly passed his lips to his eyes.

"When we do have sex..." She rasped, just loud enough to make him shiver. "You'll remember it."

Her eyes lingered on him a second longer, fluttering lazily before slipping past him and back on the route to her desk.

A grin still present on his lips, Jay's eyes followed Erin, all the while a dizzy smile never leaving his lips.