A/N: Because someone reviewed. See, it really does work.
The closing of the door broke the spell of silence on the trio - in Raj's case, literally.
"What the hell, Sheldon?!" Leonard yelled.
"How the frak did you get Penny?" Howard exclaimed.
"I can dig it," Raj said. "Congrats, dude."
Sheldon sighed and scowled. "I'm going to go change. I am not going to be the last person ready when one of our party is Penny." Of course he had nothing to worry about there; she had to shower first. But he didn't want to deal with their questions and avoidance was always his first tactic.
Howard turned to Raj, skeptical. "You can 'dig it?'"
Leonard's turn consisted of him gaping his mouth in a move reminiscent of a Sheldon's luminous goldfish, due to his flushed face. Finally he shook himself and asked, "In what way is that ok?"
Raj tilted his head. "Well, don't get me wrong, Sheldon and sex is not something I want to think about, but Sheldon and Penny make a weird kind of sense together. Opposites attract and all that."
"I mean for normal people, sure," Leonard said. "But Sheldon is the least normal person on Earth."
"And I always thought he was an alien who reproduced asexually after eating too much Thai food," Howard said.
Raj shrugged. "Maybe all it took was Penny. After so many laundry nights and Halo wins and apparently accidental kisses, maybe he finally realized he was just human enough to love."
Howard still looked skeptical, but Leonard was thoughtful.
If anyone could do it, it would be Penny.
But he was still curious. He'd practically loved her at first sight, but it'd been almost four years and Sheldon hadn't shown any interest in her before last week.
When Sheldon came back wearing his plastic breatplate and camouflage, Leonard couldn't contain his curiosity. "When did this all start? Last week you didn't look twice at her, now you're sleeping with her?"
Sheldon sat his helmet on the arm of the couch and sat down, silently relieved he'd managed to beat Penny, however small the victory. Then he figured he should probably get the explanations over with before she got back. Better now than later when he had better things to do.
"Two Fridays ago Penny, Amy, and Bernadette were playing Truth or Dare. Penny was dared to kiss me. I found that her kiss did not make me uncomfortable and wondered if it was due to her vast experience or if it was just a fluke. So two Saturdays ago while doing our laundry together I decided to test my theories, both of which needed more data, which constituted kissing Penny again. I catalogued a variety of feelings that I later identified as overall positive, along with a distaste for continuing to test my theories with other people. I concluded that it was possible that initiating the kiss myself had elevated my comfort level, or maybe it was just Penny."
Leonard raised an eyebrow. "And you were fine with that? An unfinished, biased experiment, and you're fine with it?"
Sheldon nodded. "I am happy with the facts as they are. I have no need for further exploration. Progress for the sake of progress may be the scientific raison d'etre, but it has no bearing on relationships. As I understand it, the phrase is 'If it ain't broke, don't fix it.'"
"Ain't that the truth?" Howard said.