let in on
US /let ɪn ɑːn/
UK /let ɪn ɑːn/
1.
mettre au courant de, faire part de
to allow someone to share a secret or to know something that is not known by many people
:
•
They finally let me in on their plans for the surprise party.
Ils m'ont finalement mis au courant de leurs plans pour la fête surprise.
•
She refused to let him in on the secret.
Elle a refusé de le mettre au courant du secret.