The unlikely alliance unraveled in real time, with Trump telling reporters in the Oval Office he was “very disappointed” in the tech mogul’s criticism of his spending bill, and Musk railing against the president on X.

It began with Musk complaining about the centerpiece of Trump’s legislative agenda, which the president at first took in stride. Eventually Trump let slip that he was disappointed in his former adviser, prompting Musk to unleash a flood of insults and taunts.

Musk and Trump, ostensibly political allies over cuts to federal spending, publicly clashed on June 5 in a series of exchanges across social media and in comments to reporters. The origin of the dispute is the impact Trump's One Big Beautiful Bill has on U.S. public debt.