be on (one's) best behavior

To be very polite or exercise exceptionally good manners. Primarily heard in US. Now, you kids must be on your best behavior for your Auntie this weekend! Good morning, class. I hope everyone was on their best behavior for the substitute teacher yesterday.

See also: behavior, on

Farlex Dictionary of Idioms.

See also:

on (one's) best behavior
on best behavior
on one's best behavior
on (one's) good behavior
be on (one's) good behavior
a whale of a
bundle of energy
think (someone) hung the moon and the stars
lay out the welcome mat (for one)
lay, put, roll, etc. out the welcome mat

词组	be on (one's) best behavior
释义	be on (one's) best behavior be on (one's) best behavior To be very polite or exercise exceptionally good manners. Primarily heard in US. Now, you kids must be on your best behavior for your Auntie this weekend! Good morning, class. I hope everyone was on their best behavior for the substitute teacher yesterday. See also: behavior, on Farlex Dictionary of Idioms. See also: on (one's) best behavior on best behavior on one's best behavior on (one's) good behavior be on (one's) good behavior a whale of a bundle of energy think (someone) hung the moon and the stars lay out the welcome mat (for one) lay, put, roll, etc. out the welcome mat
随便看	charge (something) on (something) charge (something) (up) to (one) charge (something) (up) to (something) charge up charge up to charge with charity charity begins at home charity mugger Charles Charley charley horse Charlie Charlie Foxtrot Charlie Irvine be in two minds about something/about doing something be in two places at once be in use be in vogue be involved with (something) be in well (with) be in with a chance be in with a shout be in/within sight be in with (someone)