A/N: I don't overly ship Leonard and Penny I'm more of a Penny and Sheldon are destined to be but this thought came into my head and I HAD to write it so here it is.
It was three in the morning and, as he fondled around on his bed side table for his glasses, Leonard attempted to recall the last time he had a full night's sleep, it had been a rough few weeks of waking up some times two or three times a night. This time however the cause of his disturbance wasn't what he was used to: he could hear a soft and slightly out of tune humming coming from the room down the hall and he'd also noticed that his beloved Penny was no longer next to him. Leonard inwardly giggled, it still amazed him that he had a wife and that an actual woman not just some robot Howard had fixed together. Glancing around to see if anything else was amiss, Leonard decided to get up and investigate; it was likely to be that Sheldon had decided he couldn't sleep and invited himself round in the middle of the night again, it was a monthly occurrence and he knew Penny wouldn't manage to shift him or at least get him into the guest room alone.
"Penny?" He called out as he shuffled towards the stairs; they always found Sheldon perched on the end of the sofa in 'his seat' reading a book or scribbling on 'his' board that he insisted on buying when Leonard and Penny bought their new house, it clearly hadn't dawned on Sheldon yet that his spare key was for emergencies or at least to just let himself in during the day. "Penny, where are you?" Leonard whispered again as he began to realize that the humming was not coming from downstairs. He turned around to face the door nearest the stairs, it was propped open and Leonard could just about make out the silhouette of his wife. He began to shuffle in and was about to ask what was happening when something suddenly brought him to a halt.
"Soft kitty, warm kitty, little ball of fur..." Leonard had to use every muscle in his body to stop himself from bursting into laughter and, as Penny slowly turned around and realized he was there, he had to try even harder as her face began to turn red.
"Where you just singing soft kitty to our daughter?" He whispered in a slightly accusatory but thoroughly amused tone.
"Oh shut up Leonard, it's the only thing that will get her to stop crying other than that god damn mobile Sheldon, Howard and Raj made her; there's only so many times you can listen to the Doctor Who theme tune." She sounded irritated but Leonard could tell that she wasn't really angry.
"Soft kitty though? Do you know how smug Sheldon would be if he knew that we found it useful?" Leonard giggled.
"Yeah, well that's why he's never going to find out." Penny playfully stuck her tongue out, softly kissed her tiny baby girl on the head and placed her back in her cot.
"Maybe we could get them to make Lydia a new mobile that sings soft kitty instead so that you can actually get some sleep, surely Sheldon's smugness for a few weeks is worth a full night's sleep?" Leonard suggested as he wrapped his arm around Penny's waist and they began to shuffle out the room.
"Few weeks? You mean years don't you?" Penny scoffed. "Fine, but you can oversee it this time, I wouldn't mind the Doctor Who mobile if they had got the volume settings right. I don't know how Lydia sleeps with that thing playing so loud, I know I can't and then Sheldon suggested I need a mobile! I know he doesn't understand double meanings but if he was trying to insinuate that I'm a baby well he's got another thing coming." Leonard tried to prevent himself from laughing again as Penny slid into bed now enthralled in a sleepy rant. "I thought he'd caught me singing to her the other week, when he came in on another one of his midnight 'I can't sleep' trips. We should confiscate his key but ooooh no, that'll be another strike on my record and I'm telling you Leonard I am not taking that class again!" Penny slid down and rested her head on the pillow and Leonard took it as a signal for him to switch the light off, as soon as he turned around she was already fast asleep snoring like a pig, all be it a beautiful and funny pig. He knew how exhausted she was and how much they both longed for Lydia to be out of the stages of middle of the night feeds and helpless crying, but still there was something beautiful about how little and perfect she was and Leonard secretly wished she'd stay like that forever.
"Good night." Leonard whispered as he softly kissed Penny's cheek and slid down into the quilt. Not five minutes later he heard the unmistakeable sound of a restless baby, looking over at Penny he knew it would be unfair to wake her up and so he crawled out of bed once again and shuffled to the baby's room. "I'm here little angel," he muttered as he scooped Lydia up into his arms. "Now, let's see, where are we?" He said before going into three more rounds of soft kitty that eventually lulled the little one into a dreamless sleep. "Oh yes, Sheldon really would be smug."
I hope you enjoyed reading this, I plan on writing some more Big Bang Theory fanfic soon but if you like Harry Potter then check out my other fics!