Bob is married to Carol. Carol's best friends with Alice whose husband Ted is best friends with Bob. Things begin to heat up (in a good way), when Bob has an affair with a woman, and Carol becomes OK with it, and hence the 2 of them openly accept that having having sex with another person is OK, as there are no emotions involved.<br /><br />For a movie made in 1969, this movie is brilliant. People tend to skip these lost gems, because they consider it to be rather 'ancient' - however it is so good, that if the same script and direction were used without any amendments, but with a different cast offcourse today, this movie would stll be a hit, and would even score at the Oscars. The performances are BRILLIANT, and are still Oscar worthy. Dyan Cannon was the most impressive - I certainly do not know how the 60's revolved, but at that time you would expect for a blonde actress, to play a quirky role. Dyan was everything BUT quirky. Natalie Wood, who i believe had a vivid resemblance to Catherine Zeta Jones, gave a good performance as well. What made their performance so good was that is seemed so real.<br /><br />A must see for everyone. Take my word - WATCH IT!