let your hair down

US /lɛt jʊər hɛər daʊn/
UK /lɛt jʊər hɛər daʊn/
"let your hair down" picture
1.

se lâcher, se détendre

to allow yourself to behave much more freely and enjoyably than usual and relax

:
It's good to let your hair down after a long week of work.
C'est bien de se lâcher après une longue semaine de travail.
The party was a great chance for everyone to let their hair down.
La fête était une excellente occasion pour tout le monde de se lâcher.