bob be marry to carol . carol best friend with alice whose husband ted be best friend with bob . thing begin to heat up ( in a good way ) and when bob have an affair with a woman and and carol becomes ok with it and and hence the 2 of them openly accept that have have sex with another person be ok and a there be no emotion involve . for a movie make in 1969 and this movie be brilliant . people tend to skip these lose gem and because they consider it to be rather ancient however it be so good and that if the same script and direction be use without any amendment and but with a different cast offcourse today and this movie would stll be a hit and and would even score at the oscar . the performance be brilliant and and be still oscar worthy . dyan cannon be the most impressive i certainly do not know how the 60 revolve and but at that time you would expect for a blonde actress and to play a quirky role . dyan be everything but quirky . natalie wood and who i believe have a vivid resemblance to catherine zeta jones and give a good performance as well . what make their performance so good be that be seem so real . a must see for everyone . take my word watch it .