Matt Damon Calls Jimmy Kimmel a 'Terrible Human Being' Amid Years-Long Feud (Exclusive)

The alleged rivalry between the actor and late-night host only escalated on the red carpet.

The heated "feud" between Matt Damon and Jimmy Kimmel rages on. Even on a red carpet, it's hard for the pair to keep things civil.

Damon walked the carpet at the premiere of his new film, Air, at the Regency Village Theatre in West Hollywood on Monday, and spoke with ET's Kevin Frazier about his long-standing (supposedly) bitter rivalry with the late-night talk show host.

When asked if he'd ever be interesting in burying the hatchet and just moving on, Damon exclaimed, "No, no, he's an a**hole. Why would I ever do that?"

"He's a terrible human being," Damon stressed. "He's a terrible human being. He's a demonstrably bad man."

Kimmel -- who has long kept up the hilarious pretense of seething disdain with his longtime friend -- walked the carpet behind him, and Damon took the opportunity to take a jab at the host.

"Hey! I'd love to take a picture with you but we ran out of time!" Damon yelled to Kimmel -- mocking the ongoing gag on Jimmy Kimmel Live, in which Kimmel apologizes to Damon at the end of every episode for running out to time and not being able to have him on.

When Kimmel got up to ET, he simply said, "You know, I don't know who that was, but yeah, I heard him. He was loud."

According to Kimmel, Damon definitely "was the cocaine bear" at this year's Oscars -- as in, the man inside the infamous bear costume -- despite Damon's staunch denial of this claim.

"Did he say he wasn't the bear?" asked Kimmel. "He was the bear."

"And totally full of cocaine," the comedian jokingly added.

When asked if they might ever reconcile on his show -- or even have an episode totally devoted to Damon -- Kimmel shot the idea down, sharing, "I just can't imagine it happening. I really can't. I think we have Ben [Affleck] on tomorrow, so we'll have that, but that will be as close as we get."

Meanwhile, Damon and Affleck's new film, Air, is set to hit theaters and be simultaneously released on Prime Video on April 5.