For HBO’s “Scenes From a Marriage,” Jessica Chastain told Vulture that she needed liquid courage and a serenade before shooting an “embarrassing” s=x scene with co-star Oscar Isaac.

Although the performers attended the Juilliard School together, Chastain found it difficult to shoot intimate sequences with Isaac.

“S=x scenes to me are embarrassing,” Chastain recently explained to Vulture. “I’m fine talking about them. For one scene, the intimacy coordinator came in after the first take and said, ‘It doesn’t look like you guys are having s=x.’ That was the note. I was like, ‘We’re not having s=x.’ [Laughs.] Both Oscar and I were like, ‘Okay, great, thanks.’”

“Oscar is such a good friend. Because I was so nervous he played music and we drank a bit of bourbon. He’d say, ‘Just pretend there’s nobody else here. It’s okay.’ And there’s a song I really like, so he’d start singing in between the takes,” Chastain continued.

Since Chastain and Isaac have known each other for more than 20 years, their on-screen chemistry as a couple navigating their broken relationships feels more real. But she claims that doesn’t lessen how awkward it is to actually film such scenes.

Intimacy coordinator told the couple to add “more up-and-down action” to their movements to make the scene appear more natural. “I know it looks sexy, but it’s not,” Chastain remarked.

She ultimately followed her co-advise star’s and paid no attention to anybody else in the room.

“I was like, ‘Okay, just lock eyes on him,’” she said. “The most beautiful part of the love scenes is the love in their eyes when they’re looking at each other. And he helped create that.”

This revelation, of course, follows the pair’s last month’s jaw-dropping red carpet chemistry that almost broke the internet. It also coincides with their press tour for the HBO miniseries Scenes from a Marriage, their second project together as longtime friends and former classmates.

Hagai Levi, an Israeli director and writer best known for creating the therapy drama “In Treatment” and the enduring Showtime series “The Affair,” is the man behind “Scenes From a Marriage.” After receiving its international premiere at the Venice Film Festival, “Scenes” started its HBO run on September 12.

The 1973 Swedish television series of the same name produced by Ingmar Bergman, which was the inspiration for HBO’s film, recounts the highs and lows of Jonathan (Isaac) and Mira (Chastainmarriage, )’s beginning with its electrifying beginning and finally ending with its collapse.

In his review of the series, Ben Travers of IndieWire says, “Affecting and exquisitely acted, Hagai Levi’s update of Ingmar Bergman’s seismic 1973 miniseries finds its own path, albeit one in parallel to many well-traveled routes. Not only does the handsome couple [Chastain and Isaac] first introduced in ‘A Most Violent Year’ still carry a casual chemistry that can be dialed up or off in an instant, but they both fight for their characters in such a way that makes them identifiable and convincing individuals.”