Guinness married the artist, playwright and actress Merula Sylvia Salaman (16 October 1914 – 18 October 2000) in 1938; in 1940, they had a son, Matthew Guinness, who later became an actor.
Alleged cottaging incident
In his biography, Alec Guinness: The Unknown, Garry O'Connor says that Guinness was arrested and fined 10 guineas for a homosexual act in a public lavatory in Liverpool in 1946. Guinness avoided publicity by giving his name to police and court as "Herbert Pocket", the name of the character he played in Great Expectations. The incident did not become public knowledge until April 2001, eight months after his death. Piers Paul Read, Guinness's official biographer, doubts that this incident actually occurred. He believes that Guinness was confused with John Gielgud, who was infamously arrested for such an act around the same period (actually 1953).