Elon Musk is known for many things, but being non-controversial is certainly not one of them.

The billionaire showed this again on Thursday as he opened up about his feud with longtime auto rival Henrik Fisker, head of EV company Fisker Inc.

The two had dated in the past after Fisker, who joined Tesla in 2007 and helped defend the first Model S, was sued a year later after Musk and Tesla alleged that he stole the company’s design technology and used it. to build new electric vehicles for his own namesake company, Fisker Coach.

Fisker and Musk competed against each other over the next few years as Fisker debuted the Karma hybrid before Musk and Tesla could bring the Model S to market. Fisker Automotive shut down in 2013 due to unforeseen circumstances, including a battery supplier bankruptcy and the loss of cars due to Hurricane Sandy.

In 2016, Fisker launched Fisker Inc., which focuses on all-electric vehicles, while Fisker Automotive focuses on hybrid vehicles.

On Wednesday, the Tesla-focused publication Teslarati tweeted an article about how executives of auto company DeLorean were being sued by Karma Automotive for “pursuing an enterprise” during the development of the company’s EVs.

Musk responded bluntly to the Tweet with his own two cents.

“How ironic, that’s what Henrik Fisker did to Tesla in 2007! Karma is a…,” Musk joked.

Fisker didn’t respond to the platform, and he couldn’t, after he notoriously deleted his Twitter account in April, shortly after Musk announced his offer to buy the social media company.

“I believe 100% in free speech. But I don’t want my free speech to be actively managed or controlled by a competitor,” Fisker wrote on Instagram at the time, in a now-deleted post. “And I don’t want a competitor to dictate how my followers experience Fisker as we grow our business. #Fisker #Love #EV.”

Tesla ran out nearly 5% in a one-year period from Friday morning.