poke one's nose into

poke (one's) nose in(to) (something)

To involve or insert oneself in an intrusive or nosy manner into something that is not one's business or responsibility. I wish our neighbors would quit poking their noses in and just leave us alone! Don't poke your nose into your brother's affairs—he can manage well enough on his own.
See also: nose, poke
Farlex Dictionary of Idioms.

poke one's nose into

Pry into or meddle in another's affairs, as in I told her to stop poking her nose into our business. This usage replaced the earlier thrust one's nose into in the mid-1800s.
See also: nose, poke
The American Heritage® Dictionary of Idioms by Christine Ammer.

poke one's nose into, to

To interfere, to meddle. This term began as thrust one’s nose into someone’s affairs, back in the sixteenth century. The analogy presumably is to a dog or other animal nosing about. Samuel Johnson used it in his Dictionary under “Nose” (1755): “To thrust one’s Nose into the affairs of others, to be meddling with other people’s matters.” In America at some point poke was substituted.
See also: nose, poke
The Dictionary of Clichés by Christine Ammer
See also:
  • poke (one's) nose in(to) (something)
  • poke nose in
  • poke your nose into
  • poke your nose into something
  • poke/stick your nose in/into something
  • thrust (one's) nose in(to) (something)
  • put (one's) nose (in) where it's not wanted
  • put nose in
  • put one’s nose in
  • put one’s nose in where it’s not wanted