don't tell me

idiom

1

—used to request that someone not give one information because one wants to guess what it is

"I know the answer." "Don't tell me. I want to guess."

2

informal

—used to show that one already knows what someone is going to say especially because he or she often says such things

"I have a favor to ask of you." "Don't tell me—I bet you need to borrow more money, don't you?"

3

informal

—used to express surprise and disappointment

"Don't tell me the concert tickets were all sold out?!" "No, I bought the last two tickets."