Title: The Gratitude Side Effect
Fandom: The Big Bang Theory
Pairing: Sheldon/Penny
Rating: PG-13
Disclaimer: Don't own them, just borrowing them for my nefarious ideas.
Spoilers: General show spoilers up through 04x19
Word Count: ~1000
Summary: Written for the help_japan effort and ladyhouston who asked for something along the lines of: "I was thinking maybe something where the two of them end up drinking together. I know it's a bit cliché, but I'd like to see one that is written well." Well, I hope this is written well. :3 Sorry about the title, I couldn't think of a good one. Thanks to kg for the beta.

Penny's relaxing on her couch when the knocks come.

*knock knock knock*

"Penny."

Penny's head tilts to the right.

*knock knock knock*

"Penny."

Penny's head tilts to the left.

*knock knock knock*

"Penny."

Penny swivels her head to look at the door and waits a beat before answering the door.

"Hey, Sheldon, what's up?"

He shifts on his feet, not quite looking at her.

"Hello? Sheldon?"

"Hello," he says.

They stand, staring at each other. Penny purses her lips.

"So...what's up?" she tries again.

Sheldon clears his throat. "Amy has pointed out a non-optional social convention that I have, thus far, been remiss in fulfilling."

Penny quirks an eyebrow.

"Come in," she says, opening the door further.

Sheldon quickly walks into Penny's apartment and stops in the center, wringing his hands.

"So, what's this non-optional social convention you're talking about?"

Sheldon makes a strange noise.

"Amy says that it is customary for friends to express gratitude to one another when one member of the friendship commits an act that is considered a 'favor' to the other."

"You...want to thank me?" Penny asks, working through Sheldon's convoluted phrasing.

"Isn't that what I just said?"

Penny stares, then shrugs. "For what?"

Sheldon flails his arms. "Why, for confronting the Cad of Carlsbad!"

Penny blinks a couple times before making the connection. "The kid who stole your World of Warcraft stuff?"

"Precisely."

"Eh," she shrugs again, flopping down on the couch. "No big deal. It was kind of fun, really."

"Nevertheless," Sheldon continues. "Without your help I not only would have lost all my gear, but also my Collector's Edition Bat'leth."

Penny shrugs again and waits.

Sheldon starts to fidget.

"Well?" she asks.

"Well what?"

"Where's the 'thank you'?"

"I just gave it."

Penny closes her eyes and sighs. She thinks to herself, "Somehow I'm not surprised. At least he tried. Sort of."

"Well," she says aloud. "You're welcome."

Sheldon turns to leave.

"Hold on a minute," Penny calls, an idea forming. "Let's celebrate our victory against the, what did you call him?"

"Cad of Carlsbad."

"Yeah, that."

Sheldon narrows his eyes at her. Clearly, he's suspicious.

"Oh, come on. I'll mix up some light drinks and," she pauses, thinking fast, "we can rewatch the latest Star Trek movie. It's a pretty good one, isn't it?"

"Penny, you know better," Sheldon admonishes.

Penny bites her lip. "You don't drink?"

"Everyone knows Star Trek IV: The Voyage Homeis the most superior of all the movies," he continues, ignoring her question.

"We can watch that one, then," she readily agrees.

Sheldon nods. "That is acceptable. I'll go get the BluRay."

Penny smirks as he practically runs through her door back to his apartment. Truth be told, she hadn't realized she'd wanted some companionship until he'd showed up at her door, but now she's kind of excited.

When he returns, she's at her kitchen island, two drinks in hand.

"What are those?" Sheldon asks as he sets up Penny's TV.

"Drinks!" she explains. "Don't worry, I made yours a diet virgin Cuba Libre."

Sheldon accepts the information and goes back to what he's doing.

Penny brings the drinks over with a tub of popcorn and settles in.

It isn't until halfway through her glass that she realizes she's accidentally swapped glasses. She looks over at Sheldon, but he doesn't seem to have noticed, so she just goes with it.

Two hours and a few very-much-not-so-virgin Cuba Libres later, the credits are rolling and Penny's more relaxed than she was when the night started.

Sheldon, on the other hand, is more than relaxed and nearly a puddle on the floor.

"Sheldon, sit up, that position isn't good for your posture," Penny says.

She reaches over and puts a hand on his shoulder and freezes, forgetting he doesn't like to be touched. But Sheldon doesn't flinch. In fact, he doesn't do much of anything.

"I never realized how different the movie would seem from this vantage point," he says, head tilted to the side.

"Oh, honey, that's definitely not good for your neck."

Penny scoots over and sits on the floor next to him, propping his head up.

"I suppose you're right," Sheldon sighs, unconsciously leaning into her touch.

"I must be more tired than I thought," he says, slumping sideways over the couch cushions.

"Sheldon, I have a confession to make."

He raises an eyebrow at her.

"The virgin Cuba Libres weren't so virgin," she says with a grimace. "I accidentally swapped the first one and when you didn't complain, well, I just made them all the same after that."

"Oh," he says, eyes furrowing.

Penny waits for the explosion that never comes.

"Well, mother will be disappointed," he says, frowning.

"She doesn't have to know, does she?"

Sheldon turns a critical eye to her. "Penny, that would be lying."

Penny meets his gaze. "Tell me, Sheldon, how many times does your mother ask you if you've had any alcohol when you've talked to her?"

He opens his mouth, clearly hoping to retort, but pauses. Penny can see him thinking, his eyes shifting back and forth.

"I suppose she hasn't."

Penny wants to feel smug, but knows this will bother him.

"How about this. If the subject ever comes up, I'll tell her, explain it was my fault, and make sure she understands you were supervised the whole time."

He perks up a little, and smiles at her. "That would be acceptable. Thank you."

Penny smirks, then, and thinks she should get Sheldon tipsy more often if that's the only way he'll express his gratitude. She immediately feels bad about that thought, knowing that Sheldon's behavior is, well, Sheldon's behavior. And, if she really thought about it, she wouldn't change him at all. Well, maybe not much. A little.

"Great!" she says, patting him on the knee.

They stare at each other for a little while, neither speaking.

"Want to watch it again?" she asks.

A beat passes.

"I'll make the popcorn," Sheldon responds, standing and making a beeline for her kitchen.

"I'll make the drinks," Penny counters. "This time, no rum for either of us, I swear."

Sheldon pauses. "I would not be…completely opposed if there was a miniscule amount of rum present."

"Why, Sheldon Cooper!" Penny exclaims, mock shocked.

"Don't tell my mother."

And Penny can't help but laugh at the tiny, mischievous smile on Sheldon's lips.

"I wouldn't dare."

The End