這個片語也可以是 pull the rug (out) from under someone’s feet

rug [rʌg] 是英文裡「(局部的)地毯」的意思

所以這個片語字面上就是「從某人的腳下把地毯拉走」

這樣做那人一定會跌倒

所以它是在說不再幫這個人，或停止對他的支持的意思

我們來造些句：

Amy’s brother decided to pull the rug out from under her and stopped giving her money.
(愛咪的哥哥決定不再幫助她，斷了對她的金援。)

He doesn’t appreciate my help, so I pulled the rug out from under his feet.
(他對我的幫助並不領情，所以我不再幫他。)

Debra pulled the rug from under her best friend’s feet. She hopes (that) this helps her get her act together.
(戴博拉中止了對她最要好的朋友的幫助。她希望這能幫她重新振作。)