Marriage takes a sour turn when a middle-aged husband falls for a young and sexy woman. Things get even more complicated when his wife starts a hot affair with a younger lover of her own.

When a polyamorous trio seems to be living its peaceful everyday life, the arrival of a girl is ready to upset their balance and change their destinies forever.

A man and woman meet by chance at a romantic inn over dinner and, although both are happily married to others, they find themselves in the same bed the next morning questioning how this could have happened. They agree to meet on the same weekend each year—in the same hotel room—and the years pass each has some personal crisis that the other helps them through, often without both of them understanding what is going on.

Follows three young millennials as they form a wholehearted ménage à trois, each of them going through a moment of transition: Fun-loving Marcello from under the thumb of his Italian soap star father, soulful French-Iranian actor Nassim toward a more fulfilling career, and artist Christine through the grief following the death of her grandfather. The trio finds joy together by joining political protests, making art, and falling deeper into their unconventional love, until Marcello must return to Italy.

The husbands of a charismatic nurse devise a plan to free her from prison when she is arrested for being a polygamist.

The story of Nola Darling's simultaneous sexual relationships with three different men is told by her and by her partners and other friends. All three men wanted her to commit solely to them; Nola resists being "owned" by a single partner.

Socialite Vita Sackville-West and literary icon Virginia Woolf run in different circles in 1920s London. Despite the odds, the two forge an unconventional affair, set against the backdrop of their own strikingly contemporary marriages.

Yeon, a student in the film department, meets Ji Hee, a smart designer, and Min Jun, a developer with an attractive appearance. The three fall in love with each other and start a polyamorous love affair.

In 1930s Australia, Anglican clergyman Anthony Campion and his prim wife, Estella, are asked to visit noted painter Norman Lindsay, whose planned contribution to an international art exhibit is considered blasphemous. While Campion and Lindsay debate, Estella finds herself drawn to the three beautiful models sitting for the painter's current work, freethinking Sheela, sensual Pru and virginal Giddy.

While traveling in Paris, author Henry Miller and his wife, June, meet Anais Nin, and sexual sparks fly as Nin starts an affair with the openly bisexual June. When June is forced to return to the U.S., she gives Nin her blessing to sleep with her husband. Then, when June returns to France, an unexpected, and sometimes contentious, threesome forms.

A Michigan farmer and a prospector form a partnership in the California gold country. Their adventures include buying and sharing a wife, hijacking a stage, kidnapping six prostitutes, and turning their mining camp into a boom town. Along the way there is plenty of drinking, gambling, and singing. They even find time to do some creative gold mining.

High school student Wendy has an odd relationship with her five friends: They're openly sexual with each other, swapping partners every week. But this is all thrown into turmoil when she meets Sean, a new student in school who has a crush on her. Wendy wants to be with Sean, but doesn't want to disappoint her friends, whom she has known since grade school. When she does decide to leave them, her best friend, Billie, threatens revenge.