Professor Marston and the Wonder Women is partially the story about the creation of the most iconic female superhero in the world, Wonder Woman. But at its core, Angela Robinson's Professor Marston is actually an intimate love story between Wonder Woman creator William Moulton Marston (Luke Evans), and the two women who inspired him most: his wife Elizabeth (Rebecca Hall) and their lover Olive (Bella Heathcote).

Robinson was particularly interested in how this polyamorous union developed over time — first as a mutual attraction and then as a sexual partnership among three consenting adults. Their love scenes are deeply sensual, which only adds to the film's intimacy. That, and there's a real tenderness to Robinson's filmmaking, which resonated with her cast.

"How are these people interacting?" Hall told MTV News, explaining Robinson's strong female gaze. "Are they all consensual? Are they all discussing their consent? What is happening to the women? How do the women experience pleasure? How do they feel strongest?"

"It's so rare that you see a film where there's a sex scene and the characters are still present in it," Heathcote added. "It's like you see these characters, and then there's a sex scene and you see two actors just trying to get through it. And then the characters pick up again after the scene finishes. Angela was determined to keep our characters alive throughout that."

In doing so, Robinson emboldened her actors to have fun during the film's more intimate scenes. Of course they had a little help from their director's sexy playlist, which perfectly set the tone for those particular scenes. "Getting ready for the first take of the first big sex scene between the three of us, and suddenly you get the first few bars of Marvin Gaye's 'Let's Get It On,'" Hall recalled.

But it was Khia's seminal "My Neck, My Back" that really got Hall, Heathcote, and Evans in the mood.

"We shouldn't tell people about that one," Hall laughed. (No, please tell us more.)

Professor Marston and the Wonder Women is in theaters now.