The first time they sleep together is unintentional.
He is delirious and she, exhausted.
"Leonard?" he calls. His voice is hoarse. There is no reply from his friend. He calls another few times, before hazarding a hopeful: "Penny?"
Nobody is home. He could place bets on the probability of their being busy when he's ill and win, but the room seems to be spinning and he doesn't think placing money on theoretical outcomes will help to resolve that. Instead, he gropes for his mobile.
Leonard's phone goes to straight to voicemail.
Penny's doesn't ring at all.
Without contemplating why he skips calling Howard and Raj, he tries the number for the Cheesecake Factory and is connected on the first ring.
"I'm dying a slow, mucus-filled death," he explains to the man on the phone. "I need to talk to Penny."
There is a pause, then: "Sheldon?"
He coughs. "How did you know it was me?"
There's a picture of him just under the register with the word 'warning' scribbled across it. They knowyou here,she thinks. "Just a hunch."
"Do you know the statistical likelihood of a person's so-called 'hunch' being correct? If you take into account –"
"I'm not being paid to listen to you, Sheldon. What's the matter?"
"My chest needs rubbing."
This is not an auspicious start to the evening.
Once again, she's been lumped with the duty of looking after a sick Sheldon.
She doesn't know where the guys have hidden this time, but she's going to kill them when they decide to turn up. Of all the dirty rotten tricks to pull twice, this has earned them a serious butt-kicking. For now though, she can't bring herself to abandon Sheldon. Even if he does make a horrible retching noise every two seconds and point out the bowl she's eating chips from is usually the used tissue bowl.
"Why don't you just use the trash can?"
"For two reasons: firstly, the bowl is portable and the garbage can is not. Secondly, the bowl is exactly 2.34 metres closer to the couch than said waste disposal unit, which means that I don't have to get up and I don't need to call on your services. You should be grateful; you don't have to handle my used tissues."
I should be grateful? For any of this? She swallows her last mouthful of chips, probably for a long time. "Why couldn't you just move the bin closer to the couch?"
"And disrupt the convenient proximity of food scraps to disposal unit in the kitchen? Come on Penny. I don't ask this very often, but think."
If looks could kill…"Boy, you're a real charmer, Sheldon."
He balks and answers uncertainly, "Thankyou?"
She sighs, figures what the hell, and starts eating again.
"Must you make that incessant crunching sound, flaunting your ability to take in sustenance easily while I lie here weakened and starved?"
"Honestly sweetie, it's the only thing keeping me from murdering you."
"Well in case it wasn't obvious, I'm hungry," he announces. She silently offers him the bowl.
He gives her a withering look. "With the fragile state my body is in, the levels of fat and sodium chloride that those pieces of reconstituted potato flakes are flash-fried in would do nothing to aid a speedy recovery," he says, as if this were completely obvious. "If anything it would hinder it."
"Let me guess. You want soup then?"
"Split pea, if you would be so kind."
That's her problem. She will be.
"Once more, please, Penny."
"Aren't you asleep yet?" she groans, her throat dry and her head pounding with the need to sleep. She's just sung Soft Kitty for the fifth time. The words are starting to lose all meaning. "You know for some big genius scientist, you seem to need simple little me a lot."
This catches him off guard because she's right: the moment Leonard is not a feasible option Sheldon knocks on Penny's door. She then, however reluctantly, proceeds to provide him with transport; advice on social situations; mind-blowing hamburgers (however biologically impossibly the adjective may be) and a smile that is not always forced. What stuns him is that he's found the word for such a relationship: he relies on her. Lying here flushed with fever, listening to her sing his childhood lullaby while she rubs his chest with ointment…Sheldon Cooper has come to rely on Penny.
"Yes, well, you're rather useful at times," he says feebly. It's hardly the strongest retort. He concedes that delirium is probably setting in, and so starts to recite the elements of the periodic table to keep his mind focused.
Penny opens her mouth wide to yawn, her muscles crying out in protest as she stretches. He's started to ramble and though she's used to that, she's not used to the hazy sheen in his usually sharp blue eyes. He looks like he's somewhere far away, and she is struck simultaneously by three thoughts:
I'm not leaving him alone while he's this sick.
He doesn't need me for anything; he just trusts me.
He trusts her to get his dinner order right, to deliver him safe into the solace of the comic book store, to explain to him the mechanics of a woman's mind. Here he is, lying bare-chested and vulnerable, and he's stopped talking and left her to take care of his body.
Her last thought is that the sudden silence means he's fallen asleep, and that sounds like a damn good idea to her.
And before she realises it, Penny is sliding from her chair to drape herself across Sheldon's blanketed feet, sinking into the warmth of his bed.
In the morning she awakes to find him glaring at her and going on about the reasons why people can not sleep in his room, but she's not listening. She's just woken from the most wonderful slumber – spent, oddly enough, at Sheldon Cooper's feet.