（某人）蠢极了，犯傻
said to mean that you think someone is being unwise
"I lent Rhoda £100 and she hasn't paid me back." "More fool you - you know what she's like!" “我借了100美元给罗达，她到现在还没还我。”“你真是犯傻——你知道她是个什么样的人！”
Well, if they knew what she was like and they still employed her, more fool them!
More fool her if she turned you down. She doesn't know what she's missing.
I mean, to be honest, if someone is willing to part with all that money without so much as a guarantee, more fool them.
More fool her for allowing herself to be so flattered by his attentions that she overlooked the obvious.
See also: fool noun (PERSON)