In other hands, the stripped-down premise of “The Lovers” — a decades-long marriage in its death throes — could be a dour experience or even an enjoyably nasty one. But writer/director Azazel Jacobs (HBO‘s “Doll & Em“) and his two leads Tracy Letts and Debra Winger bring a warm, bittersweet tone to a film that’s an endearing joy to watch. What makes “The Lovers” even more refreshing is while most cinematic romances feature characters who are legally adults, the obstacles they face often don’t feel like actual, grown-up, real-life issues. But the characters in “The Lovers” and the problems they face and struggle with feel entirely authentic, as does the magnetic chemistry between the leads. There’s an ease and familiarity between Letts and Winger that makes us believe they’ve been together for years, even if the most recent ones haven’t been happy or close.

Michael (Letts) and Mary (Winger) are married to each other, but they’re each enmeshed in committed affairs to other people: Michael with Lucy (Melora Walters), and Mary with Robert (Aiden Gillen). After the upcoming visit home from their college-age son Joel (Tyler Ross) and his girlfriend (Jessica Sula), they each plan on ending the marriage. However, a brief — and accidental — moment of sweetness between the husband and wife sparks a renewed passion. They begin lying to their respective lovers as they attempt to hide their secret rendezvous, while the date of their son’s visit grows closer.

Debra Winger, The Lovers

Jacobs’ script does an excellent job of establishing his characters and how each one relates to the others. The evolution from Michael and Mary’s hiding of their affairs from each other to hiding their trysts from Lucy and Robert is perfect, with plenty of attention paid to the little details of their respective dishonesty. There’s precision in each moment on screen, with every furtively read text or casually told lie carrying weight. But for all that’s at stake here, the drama is remarkably funny. There’s genuinely great dialogue, but a lot of the humor resides in our knowledge of these characters and how our own relationships change, deteriorate and grow. The score from Jacobs’ frequent collaborator Mandy Hoffman is a sweeping orchestral one, full of strings and emotional builds. It emphasizes that what we’re watching is a blooming romance, even though it’s between people who have been married for decades.

The combined work of Jacobs, cinematographer Tobias Datum and editor Darrin Navarro results in assured long takes that let the performances breathe. This is the luxury of having actors this good. As Michael and Mary, Letts and Winger unfurl on screen, making their characters feel remarkably human and familiar. And these are the types of performances that should be recognized come awards season. While they aren’t particularly showy and the actors didn’t undergo physical transformations, there’s nuance and authenticity in each second on screen.

Tracy Letts and Debra Winger, The Lovers

Like two of last year’s best films, “20th Century Women” and “Maggie’s Plan,” “The Lovers” feels lived-in with well-drawn characters who exist both before the movie starts and after the credits roll. These are real people with real connections to each other. The movie acknowledges the value of inventiveness and surprise in relationships, as well as the intrigue of a secret romance (even if it’s one with your spouse), while the contradictory idea of having an affair with your husband or wife is what makes the film feel so entertaining and like a fresh spin on a familiar genre. Jacobs delivered admirable work with “Terri” and Momma’s Man,” but this is the director working on another level, thanks to a beautiful marriage of filmmaker, material, and cast. [A-]

Click here for our complete coverage of the 2017 Tribeca Film Festival.