Post Infidel

The act of posting a response to the wrong status on Facebook. This person on your feed is so used to you responding to every status that you might as well be married. This person is now worried about you giving a response which has absolutely nothing to do with the status, and therefore knows you've been stepping out on him/her with another status.

Sheryl: What was up with your status about apples and then Theresa started talking about tampons?

Prudence: I know. I suspected she was a Post Infidel, but had to catch her in the act.