bú yào / zài / bèi hòu / duì / bié rén / píng tóu pǐn zú / zhè / shì / bú / lǐ mào / de / xíng wéi不要在背后对别人评头品足,这是不礼貌的行为。Don't make idle remarks about others behind their backs; that's impolite behavior.