be on somebody's case

be on (one's) case

To be constantly nagging, harassing, or annoying someone. My boss has been on my case all week to get that report done. I'm sorry for being on your case about it, but I need an answer soon.
See also: case, on
Farlex Dictionary of Idioms.

be on somebody’s ˈcase

(informal) criticize somebody all the time: She’s always on my case about cleaning my room.
See also: case, on
Farlex Partner Idioms Dictionary
See also:
  • be on (one's) case
  • be on someone's case
  • make a case that
  • off (one's) case
  • off case
  • have a case on
  • have a case on (someone)
  • in case
  • open-and-shut case
  • an open-and-shut case