(LIKE) WATER OFF A DUCK'S BACK


Meaning of (LIKE) WATER OFF A DUCK'S BACK in English

( informal ) used to say that sth, especially criticism, has no effect on sb/sth :

I can't tell my son what to do; it's water off a duck's back with him.

Oxford Advanced Learner's English Dictionary.      Оксфордский английский словарь для изучающик язык на продвинутом уровне.