Musk, 47, tweeted a screenshot of a New York Times article with the headline: "Jeff Bezos unveils Blue Origin’s vision for space, and a moon lander." The image featured Bezos, who is also the CEO of Amazon, standing in front of the company's "Blue Moon" spacecraft.
But Musk's screenshot of the article appeared to be altered. Instead of reading “Blue Moon,” the word “moon” was crossed out and the word “balls” was added in.
“Oh stop teasing, Jeff,” Musk tweeted.
The tweet received more than 52,000 likes as of Friday morning.
This is not the first time Musk has taken a swipe at Bezos. Last month, following the news that Amazon was launching thousands of satellites in an effort to offer better internet service to people living in remote parts of the globe, Musk called Bezos a copycat on Twitter.
However, the two billionaires also exchanged well-wishes as recently as February 2018 when Bezos wished Musk’s SpaceX the “best of the luck” on their Falcon Heavy launch.
Bezos announced Thursday that his space company, Blue Origin, will land a robotic ship on the moon that will carry four rovers and use a newly designed rocket engine and souped-up rocket. After that, the ship will be followed by a version that can transport people to the moon, following the same timeframe as NASA’S proposed 2024 return to the celestial body.
Last year, SpaceX announced that a Japanese businessman and a group of artists will be their first customers for a tourist trip around the moon in 2023.
The Associated Press contributed to this report.