when someone submits an FML to fmylife.com and you are involved in it.
Today, I finally convinced a girl that I liked to have sex. I decided to swoop her off the feet like the movies and carry her to my bed. I ended up hitting her head on the door frame, knocking her out. FML
Being the girlfriend would be an example of being FML'd since you did not post the fml, but you are mentioned/involved in it.