to rub salt into the wound
A: I heard your team lost today. They tell me the team was terrible, that they played awful.
B: Don't rub salt into the wound. I lost 50 dollars on the game, and I don't need to be reminded!
A: You were crazy about Liliana. She was so pretty and smart. Too bad you two broke up. I heard today she is engaged to a nice young man, and her father has given him a great job in the family business.
B: You had to tell me this? Don't rub salt in the wound, Mom. I miss her so much!