between you and me
你知我知
A: Between you and me. I managed to put the frog is Miss Young's handbag.
A: 你知我知，别告诉别人我设法把青蛙放进杨小姐的手提包里了。
B: Good old Jack! Nobody saw you?
B：好样的，杰克!没人看见吗?
A: There was not a soul in the room.
A: 房间里一个人也没有。