Catherine Corsini’s lovely, sultry Summertime, a 1971-set tale about two women of different ages and class backgrounds who fall in love, celebrates erotic abandon but never loses its mind. Unlike Abdellatif Kechiche’s Blue Is the Warmest Color (2013), France’s most notorious treatment of a sapphic sentimental education, Corsini’s movie, which takes place in Paris and Limousin, is lusty without being overwrought. The sex scenes play not as remote extreme-sports training, as they do in Blue, but as simple, primal displays of carnal appetite.

Corsini’s intelligent decisions throughout Summertime, which she co-wrote with Laurette Polmanss, surprised me given that three earlier features I’ve seen by the director (La répétition, Leaving, Three Worlds) are undone by outrageous plot complications. And although Corsini’s latest is packed with incident — the women’s movement in France provides the historical scaffolding of Summertime — the story is a simple one.

20ish Delphine (Izïa Higelin), whose surreptitious same-sexing has always ended in heartbreak, leaves her family’s farm to live in a garret in Paris, where she meets Carole (Cécile de France), a Spanish professor and feminist insurrectionist who lives with her Les Temps modernes–reading boyfriend. Each turned on by the other’s confidence, the women begin a romance that starts with an intoxicating, out-in-the-open kiss on a Paris street and continues, much more covertly but no less passionately, when Delphine must return to the southwest countryside after her father has a stroke.

In the effulgent bucolic splendor (photographed beautifully by cinematographer Jeanne Lapoirie), Delphine and Carole tend to farm chores and to each other’s bodies. The al fresco sex scenes, like those that take place earlier in Delphine’s bed in her cramped Paris flat, indelibly evince the heat generated by these lovers. But en plein air, they somehow seem less inhibited, despite the very real risks they run in the more conservative surroundings. A tangle of tongues, limbs, hair and hands, desire-drunk Delphine and Carole explore and devour. Their concupiscence is made all the more exhilarating by the leads’ bold performances.

De France, best known stateside for her roles in Clint Eastwood’s Hereafter (2010) and the Dardenne Brothers’ The Kid with a Bike (2011), here mines the strength in surrender as Carole relinquishes so much of what had previously defined her. Relative newcomer Higelin is an excellent seducer. Summertime is also boosted by terrific supporting players, namely Kévin Azaïs (one of the stars of last year’s Love at First Fight, a smart romantic-comedy reimaging) as a fellow agriculturist with a crush on Delphine, and Noémie Lvovsky as Delphine’s mother, wary and begrudgingly solicitous of her daughter’s houseguest.

For all of its wise, welcome focus on the libidinal, Summertime additionally succeeds in presenting the far-left fervor of the time without devolving into school-play pageantry. The demo-planning, infighting, mimeographing and processing among Carole and her comrades are honored — but not solemnized — as messy, necessary, never-ending labor. It is Carole’s commitment to something larger than herself that sparks Delphine’s interest, a dedication that expands and contracts as they discover just how political their most personal, intimate behavior really is.

