take the cake不止是“取蛋糕”，还可以形容“愚蠢、无礼、自私的行为”。

【例句】
He's made some silly mistakes in the past, but this one really takes the cake.
他过去曾犯过些愚蠢的错误，但是这次最甚。

You've done some stupid things before, but this really takes the cake!
你以前的确也干过些蠢事，但这一次实在吓人！