This is a very well crafted as well as entertaining movie. It is a unique blend of comedy with total seriousness. It is filled with running gags, some of which are subtle. If you don't watch and listen closely you may miss some the first time around. Then other parts are emotional and intense. Though it deals with the subject of marital infidelity, it does not put infidelity in a positive light. It shows it for the destructive vice that it is. In my opinion it is director Billy Wilder's best movie, Jack Lemmon's best performance and Shirley MacLaine's best performance.