A/N: Merry Christmas all(Unless you don't celebrate it, if not, happy holidays)! I've had a super busy week, my car broke down, my internet is out, and I've been working like a dog! I can't even remember the last time I got to sleep in past 8 am. This chapter is full of FIRSTS ;) I really think you're gonna like it!

Erin woke up with a pounding headache. As her eyes adjusted to the light, she noticed Jay wasn't curled up behind her and Ava wasn't in her crib. She frantically tried to get up to look around but again, she was met with a throbbing pain in her head and fell back onto the bed.

While she cradled her head with her hands, Jay walked in carrying an Aspirin and some water. "Morning sunshine." He said, taking a seat on the edge of the bed, next to her.

"Where's Ava?" Erin asked before popping the pills.

"In her new playpen, playing with the blocks Voight bought her." Erin nodded her head in response. "Speaking of Voight…" He trailed off, awaiting Erin's reaction, "Pretty sure he knows about us." He watched her eyes go wide and grabbed her hand, "Funny thing though- I think he's actually okay with it."

"Okay with it?" Erin raised her eyebrows in confusion. "Voight?"

After Jay had finished telling her what happened the night before, both got up and made their way to the living room, so Erin could say goof morning to Ava and Jay could get some coffee for them. As soon as Ava saw her mama her eyes lit up and she immediately dropped the toy she was playing with. Erin walked towards her and picked her, giving her raspberry kisses all over. "Uh oh, I think someone needs to be changed." She said, feeling Ava's diaper.

Erin laid her down on the couch, as she didn't have the energy to walk to her bedroom for the actual changing table, and grabbed a fresh diaper from the diaper bag a few feet away. "Kiss!" Erin's head instantly snapped up; she wasn't sure if she'd heard right.

"What was that baby? Did you say something?"

"Kiss!" Ava exclaimed again, this time bringing both of her tiny hands up to her lips; giggling slightly.

At this point Erin began to freak out, "Jay! Jay, get in here! Hurry!" She yelled.

Jay stopped staring at the coffee pot and ran out to the living room. "What is it? Is everything okay?" He asked, rushing to the couch.

"Say it again, baby." Erin said when Jay entered the room, her full attention on the infant in front of her.

There was a few seconds of silence and Erin thought she was done for the day. Jay was still confused. Suddenly a little voice filled the room again, "Kiss! Mama, kiss!" Erin reached down and lifted her up, her eyes glistening with unfallen tears of happiness. First she kissed Ava and then she kissed Jay. Erin was beyond grateful for the little family the three of them had become in the past four months. She loved that Ava had called her 'mama', although there was still that hint of insecurity hidden deep inside of her. The fear that one day, Ava's biological mom would come back and want to be a part of her life. And she didn't think she'd be able to handle that.

"What's wrong?" Erin looked up Jay. Damn him, always being able to sense her change of mood. "You're her mom, Erin. No doubt about it." He pulled her into an embrace and kissed the top of her head. "Let's get dressed, we have to go to work." Jay said as he pulled away.

Erin nodded her head again and went to put Ava back in her playpen so she could get ready for work. Before she was able to make it to her bedroom, Jay dragged her body to his and kissed her passionately. "Not gonna lie, I'm a little jealous that she said 'mama' before 'dada'." Jay said once they broke apart.

Erin let a raspy chuckle. "I can't help it if she loves me more." She beamed.

Work went better than expected. While Erin and Jay were both expecting to be pulled into to have a talk with Voight, he acted as if nothing had happened. The team busted a drug cartel and just as Jay and Erin were packing up for the night, Voight emerged from his office. "Erin, family dinner on Sunday night. Bring your boyfriend." Hank didn't wait for a reply as he zipped up his coat and descended the stairs of Intelligence. Erin and Jay looked at each other, confused. Voight knew Jay the detective, he wanted to get to know Jay the boyfriend.

Come Sunday night, Jay and Erin walked up the steps to Voight's home hand in hand, with Jay carrying Ava's car seat in his other hand. With her free hand, Erin used her key to unlock Voight's door and the three entered the threshold. Their hands unlinked when they saw Voight in order for Erin to give him a hug. "Sir." Jay said, shaking Voight's hand.

Ava started squirming in her car seat, "Mama! Mama!" The three adults in the room gave their attention to the baby in the carrier. Even Voight smiled at the way Erin was taking care of baby Ava.

"That went well." Jay said once they were in the car. "You think he likes me?" He smirked.

Erin laughed, "Actually, I think he does." Voight had learned a lot about Jay that night; his family, his life before Gabby and Intelligence. Hank was able to see how much he cared about Erin, and how great Erin and Jay worked together as parents.

"But I don't want to leave her!" Erin whined on New Year's Eve. They'd been invited to a New Year's party at Molly's, and it'd been so long since they'd gone out Jay and Erin decided to go for a few hours. The couple was in Erin's room getting ready for the night, and Ava was already out for the night.

Jay and Ava were practically living with Erin by this point, most of Ava's belongings were being stored at Erin's, and the only time Jay went by his apartment was to pick up more of his things. "She'll be fine. Lexy's gonna be here all night. We have nothing to worry about." Lexy Olinsky offered to spend her New Year's Eve babysitting, she said she 'desperately needed the money' and not to mention how fascinated she was with the 6 month old. Jay opted to give her two hundred dollars if she spent the night. Even though Ava would be asleep from the time she arrived 'til the time they got home, they wanted to make sure Lexy knew how much they appreciated her.

As if on cue, there was a knock on the door. Jay finished adjusting his tie as he made his way to the door. "Hey, Lexy." Jay stated when he opened the door. "Thanks again, we really appreciate it."

"It's no problem," She laughed, "All of my friends are out of town, and after Christmas I'm really needing some extra cash."

"Erin!" Jay called out. "Babe, Lexy's here." He tried again.

Finally, Erin emerged from the bedroom. She was wearing a black and silver sequined dress with an open back and fell just below the knees. "Should we go? I think we should stay here." Erin said once she was face to face with Jay.

"Baby, it's okay." Jay said grabbing her jacket and assisting her with putting it on.

"Okay, just- let me say goodbye one more time!" Erin attempted to go back into the bedroom but Jay stopped her.

"Nope, we gotta go. Thanks Lexy!" He quite literally dragged Erin out of the apartment, and once they were settled in the car, Erin began to relax.

The closest parking to Molly's was close to three blocks away. Erin huddled into Jay for warmth on the way and he wrapped an arm around her small frame. Upon walking through the doors, the first person Erin saw was Kelly. Great, Erin thought. The last she saw him was when she broke it off, she could already tell tonight was going to be pretty awkward. She noticed Jay point towards the table where their team was sitting. He took hold of her hand and the pair walked over to everyone else.

Kelly downed his fourth shot of the night when he saw Jay Halstead grab hold of Erin's hand. He was jealous beyond belief.

For Jay and Erin, the night was going wonderfully. They were at the perfect point between sober and drunk, and it was 11:57. "One more shot of 2014!" Ruzek yelled as he came back to their table with another round of shots. The team cheered and toasted to a new year and threw back their shots.

11:59.

"Erin! Erin!" A very drunk Kelly came stumbling towards the group, causing Jay to protectively put his hand on Erin's back, and pull her closer to him. "Erin." Kelly stated once he was in front of her, "I'm sorry for being jealous. Let's try again!

The countdown was starting. 10…9…8…7…6…

"Kelly…." Erin trailed off as the countdown continued. 5…4…3…

"C'mon, please?" Kelly begged, a smile plastered on his face. Erin only looked at him, then up to Jay.

2…1! The entire bar erupted in cheers and laughter as everyone kissed their significant other, Erin's being Jay.

Erin smiled into the kiss and didn't notice Kelly storm out of the bar in tears.

"You wanna get outta here?" Jay husked, out breath from the kiss.

Erin couldn't find the breath to put a sentence together, so her only response was to kiss him again.

They linked their hands together and quickly said goodbye to everyone before almost running out the door. They hopped in the closest cab, since neither of them were sober enough to drive, and Jay gave the driver his address.

Erin tugged on his ear with her teeth, and her hand traveled down to his groin. Jay had one hand on her waist and the other in her hair as he sucked on her neck. The cab ride was short, but not short enough. Once outside of Jay's apartment building, the couple separated so Jay could pay for the cab. The second the doors to the elevator were closed, their lips were connected again. Jay pressed Erin against the back wall and gripped her boobs.

When they reached Jay's floor, they stumbled to his door. Erin's hands explored Jay's body as he tried to unlock the door.

Finally, they were inside. Erin removed Jay's already loosened tie and started unbuttoning his dress shirt. Jay found the zipper to her dress and slipped the sequined material down her shoulders; leaving Erin in only her panties. Jay lifted her up, and she subconsciously wrapped her legs around his waist. They tumbled backwards to Jay's bed as Erin continued working on the buttons of Jay's shirt. Entering the bedroom, Jay threw Erin onto the bed and finished removing his button up and undershirt. Erin crawled to the edge of the bed to unbuckle and get rid of Jay's belt. She swiftly unzipped his pants and reached her hand inside. She could feel how hard he already was.

Jay cupped her face with his hand and brought her up to him, "Hi." His pupils were dilated as he stared into her eyes.

"Hi." She whispered, before locking her lips between his. He gently moved her backwards and lay her on the bed. Kicking off his shoes, he settled himself on top of her and kissed her lightly.

Erin could feel him between his legs, and Jay could feel the heat radiating from her. "I need you, Jay." Her voice was all but a whimper.

"Not yet," Jay smirked, making a trail of kisses down her body. Starting at her neck, Jay kissed down the valley of her breasts, stopping momentarily to gently suck on each nipple. He kissed his way down her stomach, over her belly button, and stopped when he reached the band of her underwear. He removed his hand from the breast it was massaging and slipped his fingers underneath the waistband, pulling down her underwear.

Erin arched her back in anticipation. After throwing her panties somewhere in the room, Jay went back to his trail. He kissed down her bare vulva and started to lick his way further down. He licked and suckled at the perfect speed until Erin couldn't take it anymore. "Oh, Jay!" She moaned, "Baby, I'm cumming!" Proceeding her orgasm, Jay licked up all of her juices and kissed his way back up her body, stopping at her lips.

She wrapped her legs around his waist, pulling him closer to her if possible while she came down from her high. Once composed, Erin slipped off Jay's boxers and wrapped her fingers around his manhood. "Now?" She asked, seductively.

Jay kissed her again and in one swift movement, he was thrusting inside of her. He pumped harder at Erin's request, and they kissed sloppily between moans.

"Wow." Erin said hours later, while she was tangled up in Jay's arms.

"I know." Jay said with a grin.

"That was…"

"I know."

Erin stretched her neck and kissed his lips. "Do you think Ava's okay?" She asked, "Lexy hasn't called."

Jay shook his head, stroking her arm in the process, "She wouldn't call unless something was wrong. Everything's fine; relax."

They laid in Jay's bed silently for a few minutes before Erin spoke up again, "Why don't you move into my apartment- like, officially?" When Jay didn't answer, she continued, "Think about it; you're at my place ninety percent of the time as it is, there's more space for Ava over there, and there's no point paying rent every month when you're hardly ever here." Jay was still thinking about, and didn't give her an answer straight away. "And you know it's a big deal coming from me, right? With all my commitment issues and stuff." That earned a chuckle from Jay.

He looked down and made eye contact with her, "You really sure?"

Erin's eyes widened in excitement, "Really." She contemplated whether or not to let the next words slip from her mouth, "I love you, Jay Halstead."

Jay smiled from ear to ear. He'd known he was in love with her for a long time, but never knew when to say it, "I love you too, baby." After kissing her again, he gave her the answer she was waiting for. "And I will gladly move in with you."

They made love for hours, until neither of them could physically do it any longer. Both of them fell asleep happier tonight than either had in a long time.