Dallas (Erika Linder), right, pursues Jasmine (Natalie Krill), who’s engaged to a man, in “Below Her Mouth.” The drama, in which wordless scenes are just as revealing as dialogue, feels like a love story. (Serendipity Point Films)

Sexuality, in the view of columnist Dan Savage, is like a cake with three layers. There are the people we want to sleep with, the people we are actually sleeping with, and the people we say we are sleeping with. Problems arise when gaps emerge between the layers. In the searingly sensual drama “Below Her Mouth,” which focuses on a love affair as unlikely as it is urgent, director April Mullen mines these gaps.

Jasmine (Natalie Krill) is a fashion editor living in a stylish house in Toronto with her fiance (Sebastian Pigott). He’s classically handsome, and in another film would be a leading man, but this isn’t a story about men. Before leaving on a business trip, Jasmine paints his fingernails while he’s napping. It’s an awkward action that hints at unexpressed desires.

Dallas (Erika Linder) owns her own roofing company and is working on the house next door. When her workers catcall Jasmine one morning, the two women lock eyes. But they don’t speak until a chance meeting at a party that night. Their gravitational attraction makes everything that follows feel inevitable.

Mullen and screenwriter Stephanie Fabrizi don’t waste time showing Jasmine pleading heterosexuality. Instead, she initially rebuffs Dallas by talking about her engagement (although her true feelings quickly betray her). The ensuing chemistry is electric, yet never feels like a performance. While the frequent sex scenes are graphic, they’re also driven by vulnerability and long-buried desire. In this film, wordless encounters often reveal more about characters than conversation. The film opens with the heavy breathing of Dallas and her soon-to-be ex-lover Joslyn (Mayko Nguyen). Dallas’s indifference contrasts starkly with Joslyn’s ecstasy, prompting Dallas to end the relationship.

When there is dialogue, especially in the early scenes, it can feel a bit blunt at times, but the unadorned naturalism of Fabrizi’s sly screenplay pays off in meaningful backstory. In place of monologues of reminiscence, the lovers engage in terse conversations that lead organically to poignant memories, such as the moment when Jasmine’s mom walked in on her kissing a girl and barred her from ever seeing the girl again.

Most refreshingly, “Mouth” is a love story in which the word love isn’t uttered, but felt. Krill and Linder have an understated delivery, common to the mumblecore genre. Although this sometimes works against dramatic momentum, it contrasts nicely with — and ultimately heightens — their intimate moments together.

The ambient yet groove-laden score by Noia acts like a third character, lushly sweeping through scenes while lending them a thrilling momentum. As the layers of Jasmine’s sexuality move closer together — and then threaten to fly apart — desire turns into suspense. In “Below Her Mouth,” the title can be read as a sexual allusion. But it also signals the futility of trying to hide our innate desires, let alone behind something as flimsy as words.

Unrated. At the Angelika Pop-Up at Union Market. Also available on demand. Contains strong language, nudity and graphic sex. 94 minutes.