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

1.
你知我知, 私下裡
said when you are telling someone something confidentially
:
•
Just between you and me, I think he's going to resign.
你知我知,我覺得他要辭職了。
•
What I'm about to tell you is strictly between you and me.
我接下來要告訴你的,嚴格來說是你知我知。