Elon Musk and Donald Trump have had a tumultuous relationship over the years.
While the two traded barbs during Trump's first presidency, they're now political allies.
Trump officially added Musk to join his administration to help lead his DOGE effort, and Musk calls himself "first buddy."
Elon Musk and Donald Trump are now spending lots of time together, marking a new era of their working relationship.
It wasn't always this cozy between the two billionaires, however.
Just before the 2016 presidential election, Musk told CNBC he didn't think Trump should be president.
After he won the presidency, Trump appointed Musk to two economic advisory councils, along with other business leaders.
On June 1, 2017, after Trump announced the US would pull out of the Paris Agreement on climate change, Musk resigned from his roles on presidential advisory boards.
During a January 2020 interview with CNBC, Trump praised Musk's accomplishments and intelligence.
As the pandemic gripped the US in early 2020, Musk clashed with California public-health officials who forced Tesla to temporarily shut down its factory there.