"Oh, I got calls," the 37-year-old actor-singer tells Fashion Rocks magazine. "Just friends, you know, giving me the heads-up about working with your partner."
"I thought, jeez, that's like the fourth call I got this month! What are they preparing me for?" he says. "I thought it was going to be World War III, when, in fact, it was Club Med."
Anthony plays Lavoe, a talented but troubled Puerto Rican singer. Lopez portrays Lavoe's long-suffering wife, Puchi. The 39-year-old actress-singer also produced the movie.
"We have a high standard for each other; I know what he's capable of, and he knows what I'm capable of, even more than we know ourselves," Lopez says of her relationship with Anthony.
"So when you see the light and the shine and all that someone is capable of, you want that person to achieve that. And I think he has the same thing for me."
Lopez, who married Anthony in 2004, starred in "Gigli" and "Jersey Girl" with former fiance Ben Affleck.
"We all knew the guns were pointing," says "El Cantante" director Leon Ichaso. "You know, her and another partner. ... Here we go again."
"El Cantante," a Picturehouse release, opened in theaters Friday.
Lopez is slated to perform at the Fashion Rocks concert Sept. 6 at New York's Radio City Music Hall. The concert, part of New York Fashion Week events, will air the following night in a two-hour special on CBS.
Fashion Rocks magazine will accompany the September issue of 16 Conde Nast titles.