From Longman Dictionary of Contemporary Englishdouble lifeˌdouble ˈlife noun [countable] if someone lives a double life, they deceive people by having two separate homes, families, or sets of activities, one of which they keep secretlead/live a double life Marje had no idea that her husband was leading a double life with another woman.
Examples from the Corpus
double life• In Paris, the quintessential city of freedom and discretion, he could lead a double life.• They lead a double life, on the surface passive, even servile, but inside they suffer.• Who would have thought that he was leading a double life?• It was very much a sort of double life.• She wondered how Beatrix had reacted to its revelation of the double life Maurice was leading.lead/live a double life• In Paris, the quintessential city of freedom and discretion, he could lead a double life.• They lead a double life, on the surface passive, even servile, but inside they suffer.• Who would have thought that he was leading a double life?• It's a secret that the man who led a double life has taken with his to the grave. 