*A/n Hey guys! Happy mid Saturday, how are you all doing? For anyone taking exams right now or preparing to, good luck to you and you can do it :) For everyone else, how's that hiatus life? I was going to write part two to my fanfic Curious today, but then I decided to write a oneshot so this happened. I hope you enjoy it, idk how IC it is bc it's an au but I like it :)

See you soon!

#

Flashback to nearly a decade ago, when Leonard had only been living in Sheldon's apartment for around three months. Everything was going smooth so far, he followed each and every one of Sheldon's ridiculous rules carefully (except for the couch incident) and nothing in particular bothered him. With that being said, there was always one exception.

The fact that Sheldon allowed no singing or humming in the apartment was understandable, he guessed, he classified it as "caterwauling" after all, but Leonard loved to sing, even if he wasn't good at it. He wondered how long he could go without listening to music in the apartment, or in the car, and not sing.

He sighed at the thought.

Leonard was just getting back from another day at this office, but this one was better because Sheldon didn't go with him. If this happened once every week Leonard could live with it, but from what little he knew about his new roommate, he could see how punctual the man really was, and doubted his luck.

He proceeded to open the apartment door like usual, but his jaw almost dropped to the floor as he did so.

What a load of crap.

#

(Sheldon's POV)

Living with another person reminded Sheldon of Texas in some ways. Leonard was a lot like both his siblings sometimes, but they get along and he drove him places, so the elder felt like it could be a good friendship.

While most people who live in this building didn't think of him as the "Social type", it would surprise them that at the same time Sheldon was building his friendship with Leonard, he was also creating one with the person who lived next to him.

And he admitted that, but they'd never actually spoken. Instead, they had other means of communicating, which he was still unsure about, but they were beautiful nonetheless

...She sings to him.

It didn't used to start out that way. One day he was just getting in the shower while Leonard was away, and right before he turned the water on, he paused, already naked and hopping foot to foot from the cool tile beneath him.

The melody she sang that first time nearly swept Sheldon off his feet, and he was in a daze as he prepared to get in the water. He found that when the stream of the water carried its sound through the wall she stopped, almost as if in embarrassment, but Sheldon wanted her to continue.

Except, he'd built up a reputation here in California over the past few years of not caring, not being close to other people, things like that. He was unsure of how to ask her to continue, hesitant to do so and have it lead to something more.

He's never had any friends, especially one that was a girl. Would this classify them as friends?

Sheldon listened carefully through the wall as he shampooed his hair. HIs neighbor stayed in the shower for a while longer, and sang no more, but he did hear her hum slightly, and while it would bother him if Leonard or anyone else did it, hearing the sound from her brought a slight blush to his cheeks and made his heart skip a beat.

Perhaps it was from the hot water, so he turned it down a notch.

As he was rinsing his hair he heard her shove the shower curtain open and step out into the bathroom. Sheldon had never seen her before, and didn't even want to picture her naked, but as he was focusing on lathering his loufa to wash his body, her voice rang out to him in a tune sweeter than her singing.

"Have a nice shower." He could almost hear the smile in her voice.

"Thank you," he said in an almost whisper, and then she was gone.

Sheldon hadn't joined her in singing that day, but decided to look up the song she introduced to him based off the few lines he heard.

And he learned it quick and easy.

For anyone else he would not change his schedule, but from that day on Sheldon decided to pay attention to when this woman was going to take a shower next. There was a good chance that, because she sang before in the shower, she would again, and he just had to hear her voice one more time.

That's why, the next day when she got in the shower, at the same time surprisingly, he bolted up an across the apartment, even though he wasn't supposed to for another twenty minutes.

This has easily become a routine to him, and the first time he did it Leonard looked at him like he was crazy. After that, Sheldon began requesting he leave the apartment while Sheldon showered, and Leonard began to think him insane.

He did leave though, probably to go spend time with his friends Howard and Raj, Sheldon presumed, and that's how, every night at the same time for around two hours, Sheldon got the apartment to himself.

As luck would have it, the second time he got in the shower they were getting in at the same time, and today, Sheldon said something to her through the wall.

"Hello."

It was quiet on the other end, almost as if she were questioning whether he was talking to her or not.

She didn't answer for a long time.

And Sheldon apparently had no concept of what was appropriate to do with strangers or not, so while he stood in his bathroom, again naked and she, probably the same, he decided to keep talking.

"I liked the song you sang yesterday."

What came in reply was almost a croak of a thanks, and Sheldon nodded to himself, his hand hovering above his faucet as he waited for her to say more.

"If my singing ever bothers you in the shower, just let me know."

Her tone sounded so similar to his, clinical and to the point. Her voice was now his second favorite thing he had ever heard.

"On the contrary, I happen to enjoy it." Sheldon didn't know where that came from, his sudden burst of confidence, but felt his face heat after he'd said. And then, she said something that would change everything.

"Would you like to sing with me?"

"I don't sing."

It was his immediate response, and he wasn't sure if he regretted it or not. WIth that being said, she was respectful and didn't press the issue, but she did continue to sing for him.

And Sheldon found it slowly becoming his favorite part of the day.

#

Over time the boys seemed to migrate to the apartment more and more, despite Sheldon's protests, so every day he wasn't able to sing with Amy, as he had started doing about a week before. On days with everyone there they wouldn't talk either, because Sheldon didn't want them calling him crazy anymore than they already did for "talking to himself".

Instead, exactly thirty minutes after they had taken their showers, an hour before he was supposed to go to bed, he would leave the apartment. Just get up and walk out.

The first time he did that, Leonard had been concerned. Now he guessed his roommate just figured it was another weird thing he did.

Sheldon wouldn't leave the building, though. It was almost as if he were a moth and her apartment was the flame, because he always found himself there and the first time if it was odd, he didn't think so.

The only thing he wished he'd known before hand was her name, as it made his knocking slightly awkward.

*knock knock knock* "Neighbor…"

The words sounded foreign to him as he repeated it twice, and he sighed a breath of relief that she let him finish before opening the door.

"Hello." This time, she could see his smile in his voice as he greeted her, and he could see hers in return.

"Hi."

She knew he'd come.

And for the next month, every night they would spend together, and by the end of it they had sang exactly twenty duets together, when Sheldon wouldn't allow Leonard to sing in the apartment at all. Sometimes it would be in her apartment, sometimes they sang in the shower, and all was good.

Until Leonard found out.