Add fuel to the fire

Add fuel to the fire 火上浇油

Also, add fuel to the flames. Worsen an already bad situation, as by increasing anger, hostility, or passion.This metaphor dates from Roman times--Livy used it in his history of Rome--and it remains in common use.

eg: Bill was upset, and your making fun of his mishap just added fuel to the fire.

Note:

Add fuel to the fire也可以说add fuel to the flames，意思是使本来很坏的情形更糟糕，例如让人更加生气、更加热情等。罗马历史学家李维曾用它描述罗马历史。

例：Bill很烦躁，你用他的事情打哈哈纯粹火上浇油。