know which side your bread is buttered
know which side (one's) bread is buttered (on)
To know how to best ensure one's success. I know which side my bread is buttered on, so I was very nice to the recruiter and promptly sent her a thank you card after our interview.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
know which side your bread is buttered
If you know which side your bread is buttered, you know what to do or who to please in order to put yourself in the best possible situation. Donald was a man who knew with utter clarity which side his bread was buttered. I'm in no doubt which side my bread is buttered for the present.
Collins COBUILD Idioms Dictionary, 3rd ed. © HarperCollins Publishers 2012
know which side your ˈbread is buttered
(informal) know what to do in order to gain advantages, stay in a favourable situation, etc: I’m sure Ray will make a special effort to please the new supervisor — after all, he knows which side his bread is buttered!Farlex Partner Idioms Dictionary © Farlex 2017