Once again, thank you very much for the reviews, it helps me to continue this story :)
I think there will be 8 or 9 chapters, I'll see. As Bamadude and SRAM said, Penny attacked Leonard when he came home and I've always been sort of frustrated that we didn't get to see her longing for him at the time (luckily we saw it a little bit at the start of the 7th season :) ), because she obviously did. So here is what could have happened...
Chapter 4 : Sneaking Into His Apartment
PENNY
Shoot. I'm hungry, it's 8 PM, it's raining hard outside, and I don't have many food in my apartment. Mmmm... I have a spare key Leonard gave me in case of emergency. It's an emergency, right ? They didn't eat everything before leaving, did they ? Would Sheldon notice ? Of course he would... He knew someone (me...) drank some milk. Anyway, I'm going !
In front of their door, I'm nervous. Not because I'm going in their apartment while they're not here. But because... I don't really know why, actually... Is it because I'm afraid there are too many things inside that will remind me of Leonard ? Why would that make me nervous ? Come on Penny, stop over-thinking. I open the door, and suddenly everything is so familiar. It's like I could see them greeting me. It's like I could see them seating around the table, eating. It's like I could see Leonard smiling at me. I close my eyes and slowly breathe.
Even I, I'm surprised by how I feel. Sure, I knew I was gonna miss hanging aroung with them, talking to them, eating with them, enjoying their company. But I didn't expect myself to feel this empty. I'm alone. I know it's not totally true, I have co-workers at The Cheesecake Factory, I have some friends here and in Nebraska, I have my family in Nebraska. But I learned to appreciate those four guys, I almost live with them, and now they're the ones I'm the closest with, they're the ones to who I talk to on a daily basis. Seeing their apartment empty, knowing they're all sooooo far away... I'm overwhelmed.
Finally, I decide to move. I go sitting on the couch, and I move over to Sheldon's spot and smile. I remember the time I made the cushion dirty with paint. I feel a little bit better now, thinking about them and what we did together. I'm looking around me now and searching for the jar with snakes (and money). Oh, there it is ! Another fun memory... Still sitting on the couch, I remember it's the place where I kissed Leonard twice. And I remember Christmas this year when his leg was hurt. I wonder if he took the motorbike lessons I gave him.
Suddenly, I feel the urge to be close to him again. I get up and head to his bedroom. I open the door but I don't want to turn on the light : it's like I'm afraid I could wake him up. I know, how stupid am I ? He's not here ! There's a small light from the street and the moon and I can see his stuff. I smile when I see his bat-signal, the one that Stephanie got rid of. I'm afraid to touch anything : not because he would notice or be mad, but because... It's him. Everything in there feels like him. The bed he sleeps in. The paintings on the wall. They're his. His comic books, obviously.
I sigh, realizing once more how much I miss him. Without even thinking, I climb on his bed and slip into his sheets. It feels good and I forget everything (including the fact that I came here in the first place to grab something to eat... I couldn't care less now). I wonder if he's sleeping with my special blanket right now. I wonder if he's thinking about me as much as I think about him.
I hold his pillow and I think : I miss you, Leonard.