it'll stay between us
Si tu promets de ne pas recommencer, ça restera entre nous.
If you promise not to do it again, it will stay between us.
— Mirage (2018)
Ça restera entre nous, d'accord ?
This will stay between us, okay?
— Mon cœur est déjà pris (1999)
Ça restera entre nous.
It will stay between us.
T'en fais pas, ça restera entre nous.
Don't worry, it'll stay between us.
— Dangal (2016)