That title! You’re thinking: God no, not another hetero-normative straight guy ménage-a-trois fantasy! Reader, I’m here to tell you—it’s actually not! And I would even go so far as to say this could actually be the best lesbian movie of the year—not to mention the best bisexual and best polyamorous movie of the year!

Fans of the film’s writer-director Angela Robinson (below, second from right) won’t be surprised to discover that Professor Marston is as smart, sexy, funny, and wildly entertaining as we’ve come to expect from the talent who crafted one of the all time lesbian movie classics, the 2004 teen girl spy-comedy romance, D.E.B.S.

Based on a true story, this gorgeous period production serves up an ambitious, fast-paced and pitch perfect account of the polyamorous intimacies of three fascinating characters.

The titular William Marston (played by the seriously hunky out actor Luke Evans of The Hobbit and Fast & Furious fame, below left) is the Boston-based psychologist who created the original Wonder Woman comics of the 1940s as well as inventing the lie detector. Really. The unbelievably hot Rebecca Hall (Iron Man 3, Vicky Christina Barcelona, below right) co-stars as his whip smart fellow psychologist and wife Elizabeth. And then along comes perky innocent Bella Heathcote (The Neon Demon, below, second from left) as their research assistant, Olive Byrne.

Next thing you know the inseparable trio is heading off to the lake for languid daytime picnics and grilling each other with sexy questions at the office during steamy late-night lie detector sessions. The spectacular thing about all of these scenes is that the primary emphasis is always on the interplay between Elizabeth and Olive. In scene after scene we see the evolution of their mutual passion and sizzling electric chemistry. In an early high point of the film we see William and Elizabeth spying (ostensibly for research purposes) on Olive’s sorority hazing ritual that involves Olive spanking one of the pledges. As Elizabeth’s voyeuristic arousal builds and Olive returns her gaze the scene bursts with visceral eroticism. With several subsequent hot three-way sex scenes and forays into bondage and role-play Professor Marston earns it’s R rating.

The film does a terrific job laying out the complex interplay of attractions and frank discussions of sex and power dynamics (William Marston’s DISC theory — on Dominance, Inducement, Submission and Compliance, is one of the structuring devices of the film). Set against the atmospheric backdrop of Radcliffe in the late 1920s and then flashing forward to the 1940s Robinson’s tight, elegant script deftly encapsulates this significant expanse of their lives together. As the years race past and both women have children we see this unique family constellation come up against the strictures of the era—when the college administration learns their secret they are all summarily sacked and when the neighbors discover the truth both the parents and the children are ostracized. The most wonderful thing about all of this is Robinson’s directorial quality of affection and respect for her characters and their story. The drama is never sensational; always warm, intelligent and understanding—amidst being frequently fabulously sexy.

But back to Wonder Woman. Little known fact: the original version of the comic book as William Marsden created it was jam-packed with bondage and provocative sexually suggestive scenarios. So much so that it came under fire from the Catholic Legion of Decency. Marston’s publisher eventually commands that he “cut the kink.” The film deftly weaves Marston’s Wonder Woman story with the incredible account of his two real-life wonder women to create one of the most thoughtful and sincere portrayals of polyamory ever brought to the screen. It’s worth noting that the portrayal of BDSM shares this quality of warm respect in a way also seldom seen on film. It’s a remarkable achievement.