heap coals of fire on (one's) head
To make a special effort to induce feelings of guilt or remorse in another person. Why are you citing all these examples of times I wronged you? Why are you heaping coals of fire on my head?
heap coals of fire on someone's head
go out of your way to cause someone to feel remorse. British This phrase is of biblical origin: ‘if thine enemy hunger, feed him; if he thirst, give him drink: for in so doing thou shalt heap coals of fire on his head’ (Romans 12:20).