The phrase "rubs salt into the wound" is an idiom that refers to making a bad situation even worse by adding insult to injury. It is often used to describe someone who knowingly and deliberately aggravates an already hurtful situation. Synonyms for this phrase include "pours fuel on the fire", "kicks someone while they are down", "adds insult to injury", "twists the knife" and "rubs it in". All of these phrases describe actions that are intended to make a negative situation more difficult to bear. While they may be used in different contexts, they all convey the same cruel and insensitive behavior.