Tune in but Tune out

Phrase: When you, someone else, or even a group of people listen to a conversation (most often it's an argument or fight) between others to get all the juicy details, but don't want those who are having the conversation to know that you're listening to them, tell your fellow listeners to do this. Its primary use is to prevent getting yourself or others involved in the confrontation, and allows you to listen for the details.