1
general::
Phrase(s): add fuel to the fire [and] add fuel to the flame
Fig. to make a problem worse; to say or do something that makes a bad situation worse; to make an angry person get even angrier. (Alludes to causing a flame to grow larger when fuel is added.) • Shouting at a crying child just adds fuel to the fire.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Also, add fuel to the flames. Worsen an already bad situation, as by increasing anger, hostility, or passion, as in Bill was upset, and your making fun of his mishap just added fuel to the fire. This metaphor dates from Roman times? Livy used it in his history of Rome? and it remains in common use. For similar metaphors, see ADD INSULT TO INJURY; FAN THE FLAMES.
American Heritage Idioms