SUBREDDIT: r/tifu
TITLE: TIFU by not realizing how thin my office walls are.
POST: I am a personal trainer at a large gym. I was sitting in my office with a buddy of mine who used to work here (and still comes here to workout). We have an incredibly naive and annoying woman who works in sales at our club. He and I were discussing some of the idiotic things she has said, such as: "The Spanish Inquisition is running our schools. They are a branch of the Illuminati." Now, idk what the fuck that means, but I love it. Anyways, we ended the conversation with Jake saying "*Woman's Name* is such a fuckin idiot." We looked out my office window to see her glaring at us from the lobby, along with several dumbfounded looking club members.
TL;DR: 
Buddy and I called a co-worker "a fuckin idiot" from the safety of my office. Turns out the walls are about as soundproof as a sheet of paper.