that's for me to know and you to find out

that's for me to know and you to find out

cliché I know the answer to your question, but I'm not going to tell you. Instead, you will discover it for yourself in due time. A: "Come on, what did Mom and Dad get me for my birthday?" B: "That's for me to know and you to find out! You'll just have to wait." A: "Why on earth are we taking this approach to the problem?" B: "Right now, that's for me to know and you to find out. You have to trust me."
See also: and, find, know, out
Farlex Dictionary of Idioms.
See also:
  • plot thickens
  • plot thickens, the
  • the plot thickens
  • thicken
  • do not try this at home
  • Do you know who I am?
  • Don't you know who I am?
  • be careful what you wish for(, it might (just) come true)
  • it's what's inside that counts
  • it's what's on the inside that counts