There can be no peace of mind in love, since the advantage one has secured is never anything but a fresh starting point for further desires.
George (Dudley Moore) seems to have everything going for him: a successful career writing music for movies with his lyricist partner Hugh (Robert Webber), a steady lover-friend (Julie Andrews), and a luxurious Bel Air home and Rolls Royce. But something's missing in his life: a sexual fling with the type of exotic beauty he sees cavorting with his hedonistic neighbor.
George is swept away when he sees Jenny (Bo Derek), an Ursula Andress type blonde. She easily ranks as a "10" on his scale. Through a bit of detective work, he learns that she and her husband are on their honeymoon in Mexico. George checks into the resort and makes a concerted effort to find a way to express his libidinal desires for this woman.
Sandwiched between excessive amounts of philosophizing about the male mid-life crisis are a series of top-notch slapstick sequences. Dudley Moore is a master of this comedy form. A sidebar plus for the movie is its conclusion that sexual fantasies seldom live up to their billing. Commitment may seem dreary but in the long run, it is more satisfying than swinging.