Available on Blu-ray from Mon 10 Dec 2018

Bob and Carol (Robert Culp and Natalie Wood) have driven up the Pacific Coast Highway from LA in their E-type Jag to a couples’ retreat “with no rules.” There are trust-building exercises, Tai Chi and hot tubs. The New Age has begun.

For some viewers of this adults-only comedy it will look deliciously retro, for others positively Jurassic. It’s not just the fashions but the attitudes and gender politics that seem to be from ancient history. The encounter group is helping Bob and Carol reconnect, deal with their feelings, expand their horizons and loosen their inhibitions. In the era of cults and consciousness-raising a group-hug seemed to hold the possibility of solving everything.

Then, back in LA, Bob and Carol groove to jazz rock with their pals Ted and Alice (Elliott Gould and Dyan Cannon). They kickback and light up some after-dinner Acapulco Gold (or is it, as Bob suggests, plain Burbank Brown). Bob and Carol hedge about ideas of an “open marriage” until documentary filmmaker Bob travels to San Francisco and beds a Berkeley blonde. He tells his wife and she is okay about it. But when things are reversed and Bob finds the tennis instructor making free with his missus it’s another, chauvinistic story.

The movie verges on black humour; a sex comedy late-60’s style. It’s a kind of cross between California Suite and Guess Who’s Coming to Dinner. Sadly it doesn’t have the courage of its convictions and it’s sometimes as coquettish and claustrophobic as any Doris Day vehicle; as if the hippy era never happened.

The, er, climax of the story comes when the groovy foursome take a trip to Las Vegas, that town where anything goes. Let the wife-swapping commence!

In today’s climate of toxic masculinity (not to mention Viagra, Tinder and dogging) it all looks a bit coy, not to say cop-out. When it was released – with a famous ad campaign showing all four post-coital stars propped up in bed – it seemed liberating, titillating and a little shocking. Now it’s a period piece but still with some laugh-out-loud moments and the improv ensemble cast performs well – the women have more interesting roles to play than the men. Cannon is especially good as the uptight spouse most appalled by the idea of four-in-a-bed shenanigans.