It's obvious that it's all in his head. One day Penny's going to give Raj a shot glass of ginger ale and tell him it's tequila and watch him start babbling as soon as it hits his lips.

But this is good shit, top shelf, because Leonard's celebrating a grant to do something, and when he finishes explaining what, using cocktail napkins and two stirrers and the path of his fingertip through the rings of condensation from their sweating glasses of Coke, Penny's left with the impression that he will, in effect, be counting the number of times something the size of a beach ball bounces off the moon. Every second. And that will tell him if there's ever been water on the moon, except he doesn't care about that, because, of something, because by then she's had two more shots and she whoops every time Raj takes one, drowning Leonard out. And Leonard gets that look on his face, that little furrowing of his brows, behind his glasses.

And Penny loves Leonard, really she does. She's never had what her friends call a fallback guy, the one who adores her and, even if no one else was left, would be there, in the back of her mind, her last possibility, her last certainty. Leonard loves her. Adores her. And she loves him like a quirky cousin but nothing more, and without the guilt.

It's a little weird. That she's out with Howard and Raj and Leonard. And not Simone and Jackie and Shelly.

Penny downs another shot and smacks her lips. "Truth or dare, guys! What ya got?"

Leonard orders her a couple more long island iced teas, remembering the last time she was this drunk (around him, anyway; she spent a lot of weekends drinking while they were in the Arctic or the Antarctic or wherever exactly it was), and she lets him, because she feels great.

And then she notices that Leonard is probably kicking Howard under the table, but she doesn't care, this dare is going to be the funniest thing ever.

--

It's summer and everything is reruns, which makes Sheldon complain only slightly less than he would if she interrupted his television schedule during the regular season.

"Sheldon," Penny begins, leaning against the doorway of his apartment, sliding the toe of one pump up the back of her other leg, the thin strap of her skintight blue dress sliding down her arm. She has a cocktail napkin in her hand. She had jotted down Howard's suggestions, even Raj's, except then Leonard had tipped over a tequila shot and it's all sodden and blurry, it's just something to hold while she does this.

And suddenly, this doesn't feel right at all.

"Yes, Penny," Sheldon says, exasperated, after pointedly punching the mute button on the remote, looking at her with his eyebrows up like he's doing her a favor by even talking to her.

And it's not that it's Sheldon, it's that it's Sheldon and the guys are probably listening on the other side of the door, and that she hasn't had anything to drink in an hour, and things with Sheldon never end up like she thinks they will.

"Are you in an advanced state of intoxication, Penny? If you're feeling nauseated I would prefer that you stagger the twenty feet to your own apartmentã"

"Do you ever want to have kids, Sheldon?" Penny bursts out. She was supposed to say something like biological imperative and natural selection and survival of the fittest and prime advanced specimen, or something, and Raj kept piping up with infinite diversity in infinite combinations, and nodding like his head was going to fall off. Except, and the rapidly swelling horror of this situation is sobering her up way too damn fast, the joke has to be on her. Sheldon won't have kids; Sheldon will have pods that he pats and rotates in sunlight every twelve hours like plants in a science fair project. He's going to blink at her, and yes, he does just that.

"Given that I can expect another forty to fifty years of reproductive viability, I have no wish to consider the matter as yet." He presses the mute button and it sounds like some sort of laser battle is going on, on the television.

Penny tosses the napkin in the trash, takes a few steps toward him. "So you've made the decision to not make a decision."

"Very astute of you, Penny." He has that tone in his voice, the one she's learned he doesn't actually understand makes him sound like a total jackass.

"And any woman who wanted to hook up with youã"

"'Hook up.'" His mouth twists around the words like hers does around their bizarre Klingon Boggle answers. "If by that you mean some variation on the 'friends with benefits' paradigm, I am forced to acknowledge that that scenario presents the best possibleã"

He's shifting in his seat, leaning forward, his eyes lighting up, like this is going to take a while. "You'd go for that," she shoehorns in, her fingertips brushing the arm of the couch opposite him. The other strap slides down her arm suddenly, her dress so tight that the swell of her breasts is enough to hold it up.

He shoots her the don't-interrupt-me glare, finishing whatever he was saying, and it all kind of blurs, like it was dammed up behind his teeth. "It does hold its advantages."

"So what if." Her stomach gives a little flip. He's in the plaid pants she hates and a brown t-shirt with Bigfoot on it and his fingers are long and she seems to remember some connection between fingers andã

"So what if, I..." She traces spirals on the leather arm of the couch and glances up at him, her eyes gone half-lidded, a soft pout to her lips, this is autopilot, this is child's play, and she can trust him to utterly shoot her down. And that emboldens her, and she sits down on the center cushion, shifting her knees, a soft smile lifting the corners of her mouth. He's not at all unattractive, she admits to herself, in this muzzy valley between tequila and unconsciousness. Just very intimidating, but so damn easy to manipulate, with the right, how would he say it, the right stimuli.

"Penny, while I am unsurprised that youã"

It all rushes out of her, too. "What if I wanted to hook up with you."

"While I am, and I must say flattered is not the word, since you could hardly resist the pull of my superior genes for long, and I am guessing you are at the optimal point in your reproductive cycle, if I may ask about timingã"

She shakes her head vehemently and he purses his lips.

"I hardly think the 'crapshoot,'" he folds his fingers at shoulder height in vehement air quotes, "of the genetic lottery of human reproduction would result in the most advantageous traits in any offspring we might or might not have, Penny."

"Your brains, my winning smile?" She punches his shoulder, and he gasps and rubs the spot, glaring at her like she slapped him with a two-by-four. "The best of both worlds."

"Hardly." Sheldon snorts and picks up the remote again.

"So you'd prefer Leslie Winkle to me?" She bats her eyelashes and makes her voice high and breathy, putting her palm on the cushion right next to his hips and shifting all her weight onto it.

Sheldon opens his mouth, closes it, opens it again, and this is gonna be a long one, she can tell, and she has five minutes, tops, before enough of the tequila evaporates and leaves her too sober to do this. She leans over, stopping a few inches away from his mouth, leaving her in danger of popping out of her dress, and Sheldon can't help it, his gaze flicks down for the tiniest second.

And she has him.

"Infinite diversity in infinite concentrations, Sheldon."

"Combinations," Sheldon corrects her, sounding a little haughty, just barely leaning forward, toward her.

And for someone so pale, with such limited social skills, with such easy contempt for humanity, Sheldon's not a bad kisser, not a bad kisser at all.

--

When Howard asks, Raj's eyes lit with curiosity, and Leonard a little crestfallen, Penny smiles and says they were right, there was no way she could ever have done that dare.

"Told you! You'll find pods in your shower and there will be a litter of baby Sheldons," Howard crows at Leonard, who looks more than a little relieved.

Penny directs a tight smile at her iced water and thinks about her dress hiked above her hips and very curious, very normal... irregularities under those hideous plaid pants, and how she's sure there's something to that long fingers theory.