AceShowbiz - Elon Musk is starting a beef with fellow billionaire Jeff Bezos. The Tesla founder, who was named Time's Person of the Year this week, apparently threw shade at Bezos during an interview with the Financial Times published on Wednesday, December 15.

Musk, who is also the founder of Bezos' aerospace manufacturer Blue Origin rival SpaceX, said that the latter has reasonably good engineering aptitude. However, he noted that Bezos "does not seem to be willing to spend mental energy getting into the details of engineering."

"[He] does take himself a bit too seriously," he went on to opine. "In some ways, I'm trying to goad him into spending more time at Blue Origin so they make more progress. As a friend of mine says, he should spend more time at Blue Origin and less time in the hot tub."

Bezos has yet to comment on Musk's shade.

Musk and Besoz don't have the best relationship as their companies are competing against each other. Earlier this year, Blue Origin filed a 50-page complaint to the Government Accountability Office after NASA awarded a $2.89 billion contract to transport astronauts to the moon to SpaceX. The contract tasked SpaceX with building a lunar lander that will put humans on the moon for the first time since December 1972.

In the complaint, Blue Origin believed that NASA was "moving goalposts" for the companies. "In NASA's own words, it has made a 'high risk' selection," Blue Origin argued in a statement to PEOPLE at the time. "Their decision eliminates opportunities for competition, significantly narrows the supply base, and not only delays, but also endangers America's return to the Moon."

Upon learning the complaint, Musk took to Twitter to mock Bezos' company. "Can't get it up (to orbit) lol."