The first time I encountered Bob & Carol & Ted & Alice was at the video store. I noticed the cover of the VHS tape right away: four adults laying next to each other in bed. How racy! How tantalizing! How adult! Of course, I wasn’t permitted to rent a film about swinging couples when I was a child, so I didn’t see Paul Mazursky’s 1969 free love comedy until I was much older. That’s a good thing, as I would have been sorely disappointed. The film doesn’t live up to that cover.

It’s actually much better. I wasn’t looking at the cover correctly. The four figures in that bed—Elliott Gould, Natalie Wood, Robert Culp, and Dyan Cannon—don’t look as if they’re about to engage in a spirited bout of communal extramarital lovemaking. They look happy and nervous and uncertain all at once. In actuality, the image perfectly conveys the inquisitive, empathetic spirit of the film, which grapples honestly with the realities of free love, or what is better known these days as ethical non-monogamy.

The film’s delicate tone is established in the opening scenes, when Bob (Culp) and Carol (Wood) attend a retreat at an establishment much like the Esalen Institute, which was the epicenter of a ’60s therapeutic movement to increase “human potential.” Bob is a documentary filmmaker looking for a story; Carol is there because she goes everywhere Bob does, but the two get caught up in the experience and return to their lives committed to emotional honesty. Mazursky both mocks and admires their earnest, desperate attempts at happiness, especially evident in their first dinner back in Los Angeles. When the waiter tells them he hopes their meal was satisfactory, Carol stops him and asks, “Is that how you really feel?” The poor man is befuddled by the question.

Their straitlaced best friends, Ted (Gould) and Alice (Cannon), are amused, but a crack opens in their marriage that gets wider when they learn that their friend Bob has slept with another woman. It’s not the affair that disturbs Ted and Alice. It’s that Carol, who is now committed to a marriage without a sense of ownership, doesn’t seem to mind. In bed that night, Ted makes the mistake of arguing that Bob’s real mistake was confessing the affair to Carol. Most of the film plays out like theater, with long scenes between characters that allow room for them to uncover layers of emotional reality. The actors are committed to the dance, edging closer and pulling away in equal measure, vacillating between love and anger as the moment requires. Gould and Cannon, who both received Oscar nominations for their roles in Bob & Carol & Ted & Alice, do much of the heavy lifting, wrestling their own emotions into submission over the course of several long scenes.

The sixth-highest grossing film of 1969, Bob & Carol & Ted & Alice surely spoke to its moment, when normies everywhere were wondering how they could partake in the pleasures of the counterculture, but Mazursky had his eye on something more universal. The film doesn’t end with its promised orgy, and “Age of Aquarius” doesn’t play on the soundtrack. It ends unironically with Dionne Warwick’s sweet “What the World Needs Now Is Love.” We don’t get any sex scenes; we get their aftermath, when the characters now have to rationalize their most basic urges. It’s painful and hilarious and cringeworthy, as any honest movie about sex and relationships must be. At every turn, Mazursky forgoes the chance to titillate the audience and instead keeps the film’s gaze squarely on the tender, open hearts of its characters. It shapes Bob & Carol & Ted & Alice into a lasting work that will resonate with anyone who fears their heart is hardening with age. 

Bob & Carol & Ted & Alice screens at 7 p.m. on July 19, 9:15 p.m. on July 22, and 5:30 p.m. on July 23 at AFI Silver. silver.afi.com. $13.