She’s talkin’ to him.

Lizzy Caplan teased that she gave legendary actor Robert De Niro, 81, acting advice on the set of their new miniseries “Zero Day.”

“Yeah, I told him how to do a few things,” the actress, 42, jokingly told Page Six at the New York premiere of the new Netflix show Tuesday. “I told him that acting is not just talking, it’s also listening. I told him about marks.”

“I think he learned a lot,” she deadpanned.

On a more serious note, Caplan was amazed that she got to work alongside De Niro and actress Joan Allen, who play her parents in the political thriller about a deadly cyber attack.

“Ridiculous,” she exclaimed, “Insane.”

The “Now You See Me” star, 42, plays a congresswoman in the show and said that she drew inspiration for the character from real-life politicians.

When we cheekily asked for examples, Caplan scoffed, “No, Page Six! I’m not giving out names!”

She also joked about having to play love scenes opposite Jesse Plemons, who is married to actress Kirsten Dunst.

“My friend’s husband,” Caplan exclaimed, “every woman’s dream,” before noting that the “Fargo” alum was “a dream to work with. I’m such a fan of his … We were real partners.”

The actress, who has appeared in dozens of movies and TV shows including “Party Down,” “Masters of Sex” and, of course, “Mean Girls.”

“It’s wild that that [‘Mean Girls’] still hits people,” she demurred. “It doesn’t surprise me. I think it’s genius. I thought it was genius back then.”

“It’s still relevant to every crop of new girls that turn 11, 12, they watch it,” she told us.