A Guide for the Married Man (1967) was directed by Gene Kelly and starred Walter Matthau, Inger Stevens, and Robert Morse.
Paul Manning (Walter Matthau) discovers one day that his dear friend and neighbor Ed Stander (Robert Morse) has been cheating on his wife. Curious, he asks Ed about it and is given the history and tactics of men who have successfully cheated on their wives. With each new story and tactic Paul can't help but notice the attractive blonde who lives nearby. Although Paul gets close to cheating on his wife, Ruth (Inger Stevens) he never does go through with it.
As Ed Stander (Morse) is telling Paul (Matthau) the lessons on how to cheat without getting caught, Ed's examples are told by cameo appearances and witty demonstrations.
For example, Lucille Ball and Art Carney, play a married couple which demonstrates how the husband can pick a fight to get out of the house.
Another example is shown by Jayne Mansfied and Terry-Thomas, on why one should never cheat on their wife in the home, when Jayne loses her bra.
Cameos in the examples are portrayed by Lucille Ball, Jack Benny, Terry Thomas, Jayne Mansfied, Sid Ceaser, Joey Bishop, Phil Silvers, Carl Reiner, Wally Cox, Marty Ingels, Same Jaffe, and Jeffrey Hunter.
This is a delightful comedy and Walter Matthau is darling. The witty demonstrations by the cameo appearances of some of my favorite actors are classic.