Jennifer Lopez was serious about researching her latest role.
In a recent interview with Vulture, Lorene Scafaria -- the writer-director of the Lopez-led flick, Hustlers -- reveals that the 49-year-old entertainer went to great lengths to study her character, a scamming stripper named Ramona, so much so that she got her fiancé, Alex Rodriguez, involved.
"She and Alex went and visited a strip club, and she was able to give me some… insights," Scafaria tells the outlet with a laugh.
Additionally, Lopez worked hard to get in even better shape for the role as she learned how to pole dance.
"She’s obviously such an unbelievable dancer, but she trained so hard-core for this," Scafaria says. "Pole dancing is not like anything else. It required muscles you don’t know you have. So we did treat it a little bit like a sports movie in that way."
When ET caught up with Lopez at the New York City stop of her It's My Party Tour, the "El Anillo" singer called pole dancing "probably one of the most challenging things I've ever done for a film."
"My arm is still recovering and my back. So yeah, I would say that was the hardest thing I ever did, but it was worth it," Lopez told ET. "I love this character. I love this story. It's a really gritty New York story [with] women at the forefront... To be able to produce it and star in it was very special."
In the Vulture article, Scafaria also discusses casting the film, which became "infinitely easier" after landing Lopez as the leading lady.
"The moment I finished the script, I realized, 'Oh my God, Ramona is Jennifer Lopez. Jennifer Lopez is Ramona. The two of them are the same; they have all of these similar qualities. It has to be her,'" Scafaria says. "... Everybody really, really, really wanted to work with Jennifer. That was the beauty of making this movie, too: casting what felt like the right people for each part, and watching them interact the way that they should with each other."
Hustlers, which dropped its first trailer on Wednesday, ended up with quite the cast of incredible talent including Cardi B, Lili Reinhart, Lizzo, Keke Palmer, Constance Wu, Trace Lysette and Mette Towley.
"I chased Lizzo for a year," Scafaria says. "I met with Trace Lysette probably a year earlier, then wrote her a part. I knew I needed Keke Palmer so early on. I remember casting the Mercedes character and saying, ‘It has to be Keke Palmer.’ Jacqueline Francis, who goes by Jacq the Stripper on Instagram, was somebody I knew I wanted to write a part for as well. Mette Towley was someone I’d met with probably two years earlier."
As for Cardi, it took two years of chasing her down through Instagram DM's to get the 26-year-old rapper and former stripper signed on to the project. The chasing worked, as Cardi told ET in May that she simply "had to be in this movie."
"This movie is something I can relate [to]... All the actress in the movie I can tell them, like, 'No, no, no. This is how it goes,'" Cardi told ET's Katie Krause. "... The club that the movie is based on that's... the first type of club that I worked in... This was my life."
All the work paid off with a cast who generally got along and liked each other.
"Constance and Jennifer love each other. There was this very beautiful sister relationship that was unfolding. And Keke and Lili together, they’re so adorable. Trace and Mette really hit it off," Scafaria tells Vulture. "I always feel like mom. I’m like, ‘They don’t have to love mom; they just have to love each other. We had a pretty remarkable time together; it was an incredible bond for something that was shot in 29 days with 15 women."
That bond is something Lopez also felt on the set of the film.
"I just felt like Cardi was such a natural choice, much like the other girls, Constance and Lili Reinhart, Keke... Lizzo and everybody," Lopez told ET. "We needed that cast of characters to kind of make that come to life. We needed that kind of personality from the girls, because the story really called for it. These were a special little group of women."
Hustlers hits theaters on Sept. 13.