not want to know

not want to know

To prefer to remain uninvolved in or unaware of the details of something or some situation, especially when it is illegal or unethical. A: "We could channel the profits through the offshore account, though it might not be totally legal." B: "I don't want to know—just make the numbers work!" If he's got another get-rich-quick scheme, I don't want to know about it.
See also: know, not, want
Farlex Dictionary of Idioms.

not want to know

refuse to react or take notice. informal
See also: know, not, want
Farlex Partner Idioms Dictionary

not want to ˈknow (about something)

(informal) not care about something; not want to become involved with something: She was in desperate need of help but nobody seemed to want to know. If she wants money, I don’t want to know about it.
See also: know, not, want
Farlex Partner Idioms Dictionary
See also:
  • hold the ring
  • no one will be (any) the wiser
  • not have the first idea
  • be in (one's) pocket
  • in (one's) hip pocket
  • in (one's) pocket
  • in one's pocket
  • in pocket
  • in somebody's pocket
  • in someone's pocket