"We laugh a lot," Lopez, 42, told Ellen DeGeneres in an interview with Anthony and their costar Jamie King that will air Monday.
But King begged to differ.
"Not always," he said. "I find myself in the middle refereeing sometimes. It's fantastic."
"It's true," Lopez admitted.
Any tension between her and her former husband is drummed up for TV, she says, citing a clip in which she playfully smacked Anthony – lightly.
"They put a sound effect in there," Lopez told Ellen about the footage, which never aired. "It sounds like I'm slapping him hard."
"All I did was this," she demonstrated.
"She can't help herself," snapped Anthony, 43. "Trust me, it hurt."
While their work on ¡Q'Viva! The Chosen takes the former couple around the world, Lopez and Anthony, who announced they were splitting last July, apparently don't need to go that far to find talent. Their 3-year-old twins, Max and Emme, "love to sing and dance," Lopez said.
"I think Emme has a bit of voice," the American Idol judge said. "I'm not sure, but I kind of hear it every once in a while. I'm not sure about Max as much, but he has a big personality. He's got, like, my personality. Maybe Emme has Marc's voice."