double life

noun2

1. •
   An existence or life that has two aspects, particularly when one of them is regarded as embarrassing, immoral, or unlawful and thus kept hidden from some people.

   • He lived a double life as both a British diplomat and a Soviet spy.
2. •
   The hidden, or more unusual, aspect of a person's life.

   • Counterintelligence agents discovered the British diplomat's double life as a Soviet spy.