A: Remember how dorky you looked when you got a crew cut as a child? B: There's no need to rub ...
A: Remember how dorky you looked when you got a crew cut as a child? B: There's no need to rub it in. Thank you.
I know I made a mistake, but you don't have to rub it in by keeping mentioning it.
He kept rubbing it in about how I tripped going up on the stage, so I slapped him in the face and told him to back off.
My brother failed the test, so to rub his nose in it, I told everyone about it. Later I realized it's a bad thing to do, so I stopped it and apologized to him.