ㄋㄢˊˇㄑㄧˇˇnányǐ‑qǐchǐ

难以启齿
  1. 難以開口心裡的話不好意思出來 難以啟齒」、實在難以啟齒」。

to be too embarrassed to mention sth (idiom)​, to find it hard to speak about sth