Castaway (1986)

Synopsis
Nicolas Roeg directed this dreamy erotic adventure film based on two Australian non-fiction best-sellers -- Lucy Irvine's Castaway and Gerald Kingsland's The Islander. Both best-sellers concern former clerk and waitress Lucy Irvine's response to an advertisement placed by writer Gerald Kingsland in a magazine seeking "a wife for a year on a tropical island." Irvine responded to the ad and, after learning that she would have to pay for the trip to the island of Tuin (between New Guinea and Australia), the not-very-happy couple took off to Tuin for a thirteen-month stay, after which Irvine returned to England alone. The film stars Oliver Reed as Gerald Kingsland and Amanda Donohue as Lucy Irvine. On the island, Gerald and Lucy romp around au natural and try not to get in each other's way. But then Gerald suffers a foot infection and Lucy, in spite of having seafood for every meal, begins to drastically lose weight. Gerald also gets crabby because Lucy withholds sexual pleasure from her new husband. After a year of bliss, Lucy decides to return to the British rat race, while Gerald tries to stick it out in his new island cultural environment. ~ Paul Brenner, All Movie Guide