7 Days of Lying (1963)

To keep the generous wedding gift by affluent Aunt Julia, her audacious niece and imaginary wife, Fofi, sees a golden opportunity in the person of the impecunious wandering bookseller, Loukas. The plan is daring, yet very simple: Loukas is to pose as Fofi's loving husband for as long as Julia stays in Athens, of course, in exchange for a handsome reward. Now, Loukas and his best friend, Sotiris, have no other choice but to play along. Can they survive seven days of lying?