When two people spend a lot of time together and begin to develop feelings for each other. But they actually are just assuming society's view on relationships. That people are suppose to be in pairs. So two good friends think they're in a romantic relationship.
John and Jane are both unemployed, so they have a lot of time to spend together. They start getting feelings that they mistaken as romance. They start really dating, get jobs and realize they were suffering from societal familiarity disorder (SFD)!
The action of being in a chat room, observing and silently judging all the peopleinvolved in the chat discussion(s) at a certain point in time without saying a word.
Dude #1: Dude, and then he said some weird crap I didn't even know existed.
Dude #2: You were SFDing the entire thing, weren't you?