Add fuel to the fire—(also: add fuel to the flames) aggravate discord, etc.; make an already bad situation even worse.
- Now, to add fuel to the fire, new accusations have emerged over the past several weeks that could cost Ward his position.
Add insult to injury—wound a person’s self-respect even further; add to the damage already done to somebody’s feelings.
- He was an hour late and then, to add insult to injury, he spent twenty minutes on the telephone.