The concept of the secret life is an old one in both fiction and fact. A common example would be a bisexual man pretending to be a normal heterosexual man for the purposes of maintaining a married existence with a wife at the same time as he is having sex in secret with men or boys. J. Edgar Hoover led a double life, concealing his promiscuous homosexuality from the outside world whilst being the director of the FBI.
Another example of the secret life is in the realm of real-life espionage where "agents" lead a double life- one apparent career, another quite different career…