火上浇油 ------ pour oil on the flame

例句：
A: It seems that she is in low spirits.
她似乎心情不佳。
B: Yes, she was fired by her boss. Don't bother her, or you'll pour oil on the flame.
是的，她被老板开除了。不要烦她，否则你会火上浇油。

同义词：
add fuel to the flames
like a red rag to a bull