don’t mention it—is used to indicate that thanks or apology are unnecessary:
- I wanted to apologize for not having known him in the garden. “Don’t mention it,” he enjoined me eagerly.
Note:
a) The expression does not correlate in meaning with the phrase don’t mention the war—(UK) don’t speak about things that could cause an argument or tension:
- In today’s world of “don’t mention the war” or say anything to upset the European Union, I really did believe these great little reads had long disappeared.
b) The expression does not correlate in meaning with the phrase never tell me—(also: don’t tell me) used to emphatically express incredulity or disappointment:
- “Rosalie, never tell me you’ve been talking about Alexi this whole time!” “Why, yes,” said Rosalie in dismay.
don’t talk to me about it—is used as an exclamation against discussing smth.:
- If you want to know more, read a book, or talk to Sharon or Allison. Just don’t talk to me about it anymore.
See also: don’t tell me / say no more.