Passive-aggressive behaviour is "indirect" aggression that pretends to be innocent. This means someone pretends to be nice, but is actually being mean. It can happen when people do what others want to stop direct confrontation, but they do not agree with what is ordered or suggested. A passive-aggressive person tries to hide their anger. For example, "I would have had a good day if I hadn't been cleaning up someone's mess". This sounds okay when someone first reads it, but it is actually them being mad at the person who made the mess.