Sheldon and Penny have kept their meeting a secret from everyone, because really, its no one's business but their own.
And honestly, who wants to hear anyone's negative thoughts?
So Penny and Sheldon meet every Saturday for laundry and discuss their next meeting that Saturday. Penny likes to call them encounters, or sometimes crudely, a booty call.
Sheldon does not see it this way, sure they engage in coitus from time to time, but their 2 A.M meeting on Saturday don't always consist of sex. They are just content with each others company.
Some Saturdays Penny would need him to just comfort her with some cuddles and talking. Some Saturdays Sheldon would vent about his colleagues or his roommate.
Some Saturdays they said nothing, because there was no need for words when they could be showing each other how they felt.
Some Saturdays, they said nothing, but this wasn't because they could show it, its because they were content listening to each others even breathing and their heartbeats that fell into sync.
Read the rest via the link in the description!