WATCH: The Siren cast tells us how Mermaids mate

Long before Siren premiered on Freeform, fantasy fans had to wonder: how exactly do mermaids mate? Within water, all of their necessary parts appear to be, shall we say, fishy. On this week's episode of Siren, we got our first real glimpse at how the undersea mating is supposed to work.

One of the funniest moments in the episode came when Ben (Alex Roe) asked Levi (Sedale Threatt Jr.) about mermaid mating rituals. Levi wasn't shy about demonstrating the way males of his species attract a mate.

Amusingly, the episode was helmed by John Badham, the director of Saturday Night Fever. The cast couldn't resist breaking out a few of the '70s classic songs to dance to as an homage to Badham's most famous film. But it was series star Eline Powell who connected the dancing with the sensual side of mermaids. Especially Levi's dance in the episode.

"I love the way Levi does those movements," said Powell. "You know, somebody who has to understand rhythm and move to rhythm. Even though I do think mermaids are very in tune with their bodies, I think this particular way of human is unique."

The episode also featured a significant development in the complicated relationship between Ryn, Ben, and Maddie. But in this particular video, Powell reflected on her own dance with Roe.

"So, the way it goes is the first couple of takes, we'll actually play the music," recalled Powell. "But then it's cut off, so you’re in this moment, swaying and actually... it's okay. I listened to [Roe's] heart."

For more details, check out the entire clip! Siren airs Thursdays at 8PM on Freeform.