be like a red rag to a bull
US /bi laɪk ə rɛd ræɡ tu ə bʊl/
UK /bi laɪk ə rɛd ræɡ tu ə bʊl/

1.
像給牛看紅布, 惹人生氣的事物
something that is very likely to make someone angry or upset
:
•
Talking about politics with him is like a red rag to a bull.
和他談論政治就像是給牛看紅布。
•
Criticizing her work is like a red rag to a bull; she gets furious instantly.
批評她的工作就像是給牛看紅布;她會立刻暴怒。