closet case

noun2

1. •
   (slang) A person who conceals or denies their sexuality or gender identity.

   • Even self-styled liberated gay and straight people sometimes call outspoken bigots "closet cases". — 1979
2. •
   (slang) A person who is shunned, ignored, or considered to be an embarrassment.

   • Closet case at Delta Upsilon is shunted to the basement.... — 1956