it's none of my business
Non devi dirmelo, non sono affari miei.
You don't have to tell me; it's none of my business.
— Non dirlo a nessuno (2006)
Io lo so che non sono affari miei.
I know it's none of my business.
Non sono affari miei, ma come sei finito qui?
It's none of my business, but how did you end up here?
— Vite vendute (1953)
It's none of my business!