It's been three days since Amy and Sheldon kissed.

Three whole agonizing, irritating, frustrating days.

She can't stop playing that kiss over and over again in her mind, reliving each delicious, wonderful moment of it - the touch of his lips as they forced themselves against hers, the way they softened after a moment, the way he pulled closer, the way his hands found her hips and held her…

It's caused enough of a distraction that she's fallen behind on work in her lab. While she was supposed to be monitoring the effects of cocaine on a starfish, she was in fact daydreaming about Sheldon's lips and hands and completely ignoring the twitching, hyped-up creature in the tank before her. Luckily, she has video recordings of the experiment from which she can extrapolate the data she missed, but any more lapses like that could lose her her job at CalTech.

Which is why she's frustrated. Because the biggest moment of her life is still a secret she hasn't shared with anyone.

She wants to tell Penny, her best friend, in person; before bed the night of the kiss she texted Penny a nearly incoherent "I HAVE SOMEYHTIUGFN IMPORTYANTY TO TELL YUOI!" to which Penny had immediately responded "What happened?!" It took all her willpower to keep herself from spilling the story through her fingertips into that small screen, but she held back.

"I need to tell you in person!"

How she regretted those words.

Because on Sunday night, when they returned, Penny was in a meeting with her agent and getting new head shots done.

On Monday, Penny was on her way to CalTech to talk to Amy at the lab when she got a call-back for a fast-food commercial for which she auditioned the week before. The call-back took most of the day, and by the time Penny got out Amy had already been dragged to the model train store by Sheldon, who shared shy, secretive glances with her over the locomotive displays.

Amy never realized that a blushing Sheldon could be so attractive and adorable, simultaneously pulling at her heartstrings and… other strings. But he was, and so she completely forgot that she had a best friend, that she was a human being, that she knew what words were, that she could breathe.

Now, it's Tuesday, and Amy's going mad. She wants to scream her secret out in the cafeteria at CalTech. She wants to run through the streets of Pasadena, sharing her joy. She wants to dance while she works and sing at the top of her lungs and let everyone know that she, Amy Farrah Fowler, is happy.

But most of all, she wants to tell her bestie that she finally got a real first kiss from her boyfriend.

They all meet up for dinner at the Cheesecake Factory. Even though Penny doesn't work there anymore, the restaurant is still part of the 'Sheldonian Calendar', as Howard has dubbed it. Now that Penny is sitting with them, rather than serving them, they need a bigger table; when the kerfuffle has settled, Penny and Amy are seated directly across from each over, squeezed between the rest of their closest friends.

"What is it you wanted to tell me, Ames?" Penny asks. All eyes turn to her and she blushes madly, stammering for a few torturous moments before regaining control of her faculties.

"I'd… like to tell you in private."

Penny frowns, opening her mouth to respond, but they're interrupted by the arrival of Nancy, their new waitress. The meal progresses slowly, the conversation full of stories from the weekend. Raj gets his share of jeers and catcalls as he talks about Yvette, who he's been texting non-stop since meeting her, and Penny defends herself against Leonard's teasing accusations that she 'called in' her gift to him. Through it all Amy tries to contribute, but having release so close yet so inaccessible is driving her mad. She's bouncing her heel and toying with her silverware, chewing the inside of her cheek and fiddling with a button on her cardigan until it comes loose and she has to shove it into her pocket so she doesn't lose it.

Nobody notices. Sheldon's elbow is digging almost painfully into her ribs due to their proximity, and he doesn't notice. Bernadette's skirt is spread over Amy's lap, and she doesn't notice. She's completely alone in her mental anguish.

She feels eyes on her and looks across the table to see Penny staring at her, her beautiful brow wrinkled in concern. Amy could cry, because Penny is noticing her discomfort; Penny can see how tormented she is.

Amy knows that she inserted herself in to Penny's life; that their "best friendship" is likely one-sided. She doesn't need Penny to prove herself. It's enough that Penny tolerates her presence in her crazy, beautiful life.

Penny closes her eyes for a moment, clearly thinking hard, and Amy can't help but watch her with interest. Penny is usually open and honest, earnest in all things, crass and candid and gorgeous and perfect; it's strange to see her concentrating so fully, clearly choosing careful words and careful thoughts and stringing them together with circumspect precision.

When she opens her eyes, they lock into Amy's. The world seems to slow down as the winsome blonde opens her mouth and speaks.

"Op a gop pop, hop e-ay top top?"

Everyone stops speaking and stares at Penny. Penny is unabashed, ignoring their eyes and watching Amy closely. Amy can barely see her best friend, because her own eyes have filled with tears.

Penny remembers. She hadn't seemed to pay attention to Amy's explanation of her secret language years before, but clearly she had. Clearly she remembers, because she just asked 'If we use this, can you tell me what's up?'

"A dop-dop pop e-ay bop." 'Sheldon kissed me.' It's all she can say, because she's full on crying now, tears of joy streaming down her face and gathering at her throat. Penny's eyes widen and she lets out a shriek, leaping to her feet and crying out "BATHROOM. NOW!"

Amy struggles out of her seat and follows Penny to the bathroom - not that she has a choice; Penny has grabbed her hand and is dragging her across the restaurant. The friendly gesture is enough to make Amy let out an even louder sob, and as soon as they make it into the ladies' bathroom she throws herself into Penny's arms and the women hold each other until the tears stop, then hold each other as Amy describes the kiss, then hold each other as Penny squeals and giggles and hops around in excitement.

Amy thought she never needed Penny to prove herself; if she's honest, she never expected her to.

But now she has.