Not rated, would probably be PG-13-Some Suggestive Content
Nudity is only implied in this movie by showing things like a strapless back and the sides of breasts. Some women wear clothing that is semi-transparent.
A mixed group of adults are shown skinny dipping at night and having a grand time.
A man interrupts a woman while she's taking a shower.
Sex is implied by evening fade outs in bed followed by morning fade ups in bed with implied nudity. This occurs three times involving the same woman with two different men--once as a single woman, once with her husband, and once with the first man. There are implications that these are not the only two men she's been with.
A married man propositions a woman to become his kept woman.