rub salt in the wound

• rub salt in someone's wounds, rub salt into the wounds

Derived from the stinging sensation of salt deliberately being rubbed into an open, bleeding wound.

rub salt in the wound

1. (idiomatic) to make an injury, physical or emotional, feel worse

   Synonyms: add insult to injury, kick someone when they are down, twist the knife, rub it in

• For rub, one can substitute verbs such as add, pour, put, possibly requiring a change in the preposition in.
• See salt in the wound for variations in that portion of the expression.