sour grapes
嫉妒自己得不到的东西，因此贬低或轻视它
口语·形容嫉妒心理
英文释义
to disparage or belittle something that one desires but cannot have, or is no longer desirable
例句
She said the prize wasn't worth winning, but that's just sour grapes.
典故来源
源自伊索寓言《狐狸与葡萄》，狐狸吃不到葡萄便说葡萄酸，比喻贬低得不到的东西。