Title: How to Save a Marriage and Ruin Your Life
Year: 1968
Actors : Tony Curtis, Dean Martin, Janet Leigh, James Whitmore, John McIntire
Plot: Battle of the sexes comedy about a free-wheeling bachelor who decides to save his friend's marriage by proving that all mistresses are incapable of fidelity. The plot gets complicated when the bachelor offers to set up the wrong girl in a lavish love-nest and she accepts, thinking it to be a marriage proposal.