A: You know that this means you won’t get to qualify for the state championships, right?
B: Sheesh, no need to rub it in, Dave.
A: I’m going to Europe with the money I won the lottery.
B: I already know that. You don’t need to rub it in!
Note: If someone “rubs it in,” they keep talking about something that makes you feel embarrassed or upset. Or, they keep flaunting their success or good fortune in order to make you jealous. This idiom alludes to the expression “rubbing salt into a wound,” an action that makes the wound more painful. It dates from medieval times and remains current.