Business tycoon Steve Wynn learned the hard way that it's not a good idea to talk about any of George Clooney's personal friends while in his presence after the Oscar-winning actor stormed out of a dinner over his criticism of the president.

According to the New York Post's Page Six, the 52-year-old Hollywood star blew up when the 72-year-old casino magnate called President Obama a derogatory name while they were having a business dinner two weeks ago in Las Vegas. 

Sources said that Clooney was in town with his partners to promote their Casamigos tequila during the Wine and Spirits Wholesalers of America convention. Before attending a party, Clooney and his business partner decided to have an early dinner with Wynn, his wife, and other associates at the Botero, a restaurant inside of Wynn's Encore hotel. However, things got nasty when Wynn, a Republican and Obama critic, began speaking about the president in a crude manner.

"Wynn was provoking George, talking about politics. At first George just wasn't responding. He just sat there politely listening," the source said. But, "Steve kept pushing and pushing then started raising his voice. George still didn't respond. He really didn't want to get into it."

However, the "Gravity" star finally erupted when Wynn criticized Obama and the Affordable Care Act.

While "discussing Obamacare, Steve called Obama 'an a - - hole,'" the insider said. "George responded, 'President Obama is my friend. Don't talk about him like that.' Wynn then shot back, 'Your friend is an a - - hole!'

"George glared at Steve and said, 'No! You are an a - - hole, and I'm not going to sit here anymore and listen to this!'"

Clooney then released a statement about the chain of events that led to his outburst, USA TODAY reported.

"He called the president an [expletive deleted]. ... That is a fact. ..." Clooney said. "I said the president was my longtime friend, and then he said, 'Your friend is an [expletive deleted].' ... At that point I told Steve that HE was an [expletive deleted], and I wasn't going to sit at his table while he was being such a jackass."

"It had nothing to do with politics and everything to do with character," Clooney's statement said.

In response, Wynn, a major Republican Party donor, told his side of the story, telling the Las Vegas Review-Journal that Clooney was drunk and initially became upset at the dinner when one of the business executives told a joke about former Soviet President Mikhail Gorbachev.

Clooney threw "a hissy fit" over the comment, Wynn said. Wynn added that Clooney brought up Obamacare and then got mad when he offered his opinion.  

"Then he sat down and started talking about the Affordable Care Act, and that's when I spoke up. He didn't like that either. I think my discussion about the Affordable Care Act was the straw that broke the camel's back. When he's drinking, he considers himself a close personal buddy of the President," Wynn said. "Clooney's fun to be with when he's sober. If you have a chance to drink with him, you want to get there early, and don't stay late."