water off a duck's back

Meaning

1. (like) water off a duck's back

   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.

From the same entry

• by water
• it's water under the bridge
• like water
• not hold water
• waters break
• blood is thicker than water
• blow out of the water
• pour cold water on
• dead in the water
• in deep water
• dip a toe in
• like a duck to water