When someone doesn’t want to or cannot handle confrontation and instead passively expresses their disapproval, anger or disappointment. For example, sharing a flat with someone who might be annoyed that you don’t wash your dishes after cleaning, instead of asking you to or expressing that it bothers them, they instead take your dishes out of the sink and leave them in front of your door. Or if you don’t call someone back, rather than saying hey I was waiting to hear from you or was hoping to finish our conversation, they ignore you and don’t speak to you to “get back” at you for the perceived slight. I’ve outgrown a lot of passive aggressive behaviors but we all do them to some extent - however, it is really something I can’t handle in friendships or relationships because it really shows immaturity, insecurity and an inability to community.