George Clooney says that he walked out of a dinner with high-profile casino owner Steve Wynn after Wynn insulted his "longtime friend" President Obama.

The “Monuments Men“ star, who raised millions for Obama’s reelection campaign in 2012, was reportedly in Las Vegas to promote a tequila brand when he got into a heated discussion with Wynn.

“He called the president an asshole ... that is a fact ... I said the President was my longtime friend and then he said ‘your friend is an asshole,’ ” Clooney said in a recent statement to the Las Vegas Review-Journal, which first reported the dustup.

“At that point I told Steve that he was an asshole and I wasn’t going to sit at his table while he was being such a jackass,” the 52-year-old entertainer said.

Clooney concedes that “there were obviously quite a few more adjectives and adverbs” used by both men before the Oscar-winning actor walked out of the get-together.

Writes Clooney, “It had nothing to do with politics and everything to do with character.”

Wynn, one of the richest men in the world, told the paper that Clooney “threw a hissy fit” at one of the other dinner guests.

“Then he sat down and started talking about the Affordable Care Act, and that’s when I spoke up,” said Wynn, who has criticized ObamaCare in the past.

“He didn’t like that either. I think my discussion about the Affordable Care Act was the straw that broke the camel’s back,” Wynn said in a phone interview, adding of Clooney, “When he’s drinking, he considers himself a close personal buddy of the president.”

Clooney is well known for his involvement in a variety of political and humanitarian causes. Clooney's rep told ITK on Tuesday, before news of the Obama argument broke, that the actor would not be attending this year's White House Correspondents' Association dinner in Washington next week.