Joaquin Phoenix Embarrassed By 'Diva' Behavior In 'Joker' Outtake

Joaquin Phoenix was "embarrassed" by a "Joker" outtake shown on "Jimmy Kimmel Live" on Tuesday.

In the footage from behind the scenes of the upcoming DC Comic movie, Phoenix, in full villain make-up, took issue with the "constant whispering" of cinematographer Lawrence Sher. "Just shut the f--k up, dude. I'm trying to find something real," growled the star.

Sher, in turn, called the actor "Cher" for his "diva-like" behavior. "It's not even an insult," Phoenix shot back. "Cher, really? She's a singer, actor, dancer, fashion icon. How is that a f--king insult?" added Phoenix before he stormed off set yelling "I can't do this man!"

After the short clip wrapped, the "Walk The Line" star appeared flustered and said it was "embarrassing" to watch. "Sometimes movies get intense. You have a lot of people in a small space and you're trying to find something. That was supposed to be private, I'm sorry you guys [the audience] had to see that."

But Phoenix and host Jimmy Kimmell seemed to be in on a joke together as they riffed about who was truly at fault.

"I blame Larry," said Kimmel. "I blame Larry too... no, no" replied Phoenix. "It's totally Larry's fault," continued Kimmel.

"And it's Cher's fault in a way, too," quipped Kimmel. "Cher does have some of the burden to take on this," he added before laughing.

Phoenix ended the interview with a public apology/non-apology to the cinematographer.

"I am sorry..." he said before a long pause. "But he did whisper constantly while we're trying to work, and sometimes it's really hard to find the emotion you're after... he shouldn't have done it," the actor said with a grin.

While the clip may have been a gag, director Todd Phillips revealed "diva-like" tendencies from Phoenix and co-star Robert De Niro during the making of the film in a recent interview with Vanity Fair.

De Niro demanded a read-through of the script with the entire cast before shooting began, while Phoenix, who prefers minimal rehearsing, said "There's no f--king way I'm doing a read-through," according to Phillips.

"I'm in between a rock and a hard place," continued Phillips. "Bob called me and he goes, 'Tell him he's an actor and he's got to be there, I like to hear the whole movie, and we're going to all get in a room and just read it. I do read-throughs before we shoot, that's what we do.'"

Phoenix eventually agreed, but "mumbled his way through the script" at De Niro's offices in Manhattan. And immediately following the read-through, when De Niro asked for a personal meeting between the two leads, Phoenix declined. "He's in front of Bob, and he goes, 'I can't, I gotta go home,'" detailed Phillips, "because he felt sick after that read-through, he didn't like it."

After some convincing by Phillips, the two actors "talked over a few minor issues" and De Niro took Phoenix' face in his hands and kissed him on the cheek saying "It's going to be okay, bubbeleh." "It was so beautiful," said Phillips.

But it was unclear if their differences were ever settled as they barely acknowledged each other while filming, even if they chalked it up to their acting methods.

Phoenix, playing the titular character as a mentally ill loner named Arthur Fleck, said: "I didn't like to talk to him on set. The first day we said good morning, and beyond that I don't know that we talked much."

"His character and my character, we didn't need to talk about anything. We just say, 'Do the work. Relate as the characters to each other.' It makes it simpler and we don't [talk]. There's no reason to," agreed De Niro, who portrays a late-night talk show host.

"Joker" opens in theaters October 4.