Mr. & Mrs. Smith (1941)

New York sophisticates David Smith and Ann Smith née Krausheimer have been lovingly and passionately married for three years, or so they believed. They are told individually that due to a technicality - an unresolved municipal and state jurisdictional issue at the time of their supposed marriage - their wedding was not legal, and as such they are not really married. Despite David saying earlier in the day that if he had to do his life all over again that he would not have married her (even though he loves her), it is Ann that decides not to marry David this second time around due to an action, or in reality inaction, by David in reaction to the news of their marriage being invalid. While Ann goes about her life as a supposedly single woman (which includes calling herself Ann Krausheimer), David does whatever he can to win Ann back. But winning Ann's hand may be difficult as part of Ann's new life is dating other men. One of those other men and the most serious is David's best friend and business partner, Jefferson Custer. Ann and Jeff's relationship quickly gets to the point where Jeff introduces her to his visiting parents, with who Ann and Jeff are going on a skiing vacation to Lake Placid. David hopes to exploit that vacation in order to win Ann back.