between you and me
US /bɪˈtwin ju ænd mi/
UK /bɪˈtwin ju ænd mi/

1.
między nami, w tajemnicy
said when you are telling someone something confidentially
:
•
Just between you and me, I think he's going to resign.
Tak między nami, myślę, że on zrezygnuje.
•
What I'm about to tell you is strictly between you and me.
To, co ci powiem, jest ściśle między nami.