踩腳後跟

Simplified: 踩脚后跟

cǎijiǎohòugēn ㄘㄞˇ ㄐㄧㄠˇ ㄏㄡˋ ㄍㄣ

    • to slander or harm someone behind their back

Character by character

Saying俗语俗語

Idiom惯用语 · Rarely used now

Literally
step on someone's heels
Meaning
To slander or harm someone behind their back when they are off guard. Critical.

Sources