know who can help one and try to please him, know what is good for oneself He is careful not to make his boss angry. He knows which side his bread is buttered on.
KNOW WHICH SIDE ONE`S BREAD IS BUTTERED ON
Meaning of KNOW WHICH SIDE ONE`S BREAD IS BUTTERED ON in English
English idioms vocab. Словарь английских идиом и выражений. 2012