When you are in a joke relationship on facebook, and you have to break the news to your friend that you are ending your relationship status with them. (usually becuase there is an actually relationship you just got in)
Similar to a Facebook Breakup, except you real-life interactions generally remain the same. The breakup is ONLY on facebook.
"Hey. Karl didnt take the status breakup so well. He still wants to be in a Civil Union"