The spat between SpaceX CEO Elon Musk and Delta Air Lines CEO Ed Bastian is escalating.

The issue is Starlink, SpaceX's space-based broadband product that serves millions of customers, including airlines. Delta passed on Starlink in the spring, opting for Amazon.com's space-based broadband product, called Amazon Leo. Delta now uses T-Mobile, with the help of Viasat, and will roll out Leo in 2028.

The decision irked Musk, who tweeted in May: "Delta wanted to make it painful, difficult and expensive for their customers. Hard to see how that is a winning strategy." That was it for a while.

Recently, however, Bastian addressed the company's choice of provider with employees at an internal meeting, according to multiple reports. "We do not want to be with Elon Musk. Trust me," said Bastian, adding, "If you know his reputation, it's all true what they say about him."

Delta didn't immediately respond to a request to verify the remarks.

Musk didn't seem happy with those comments, tweeting on Tuesday, Bastian "will lose his job over this," and taking some other shots at Delta's in-flight Wi-Fi service.

Good Wi-Fi can certainly be a competitive advantage. Barron's used Starlink on an Alaska Air flight, and it was very impressive. More than a dozen global airlines use it, including United Airlines, but there are plenty that don't.

On the other hand, an airline executive's job security comes down to a lot more than in-flight Wi-Fi service. Fleet strategies, employee relations, credit card partnerships, airline scale, and operational efficiency all matter-a lot.

And Delta stock has been a relatively strong performer. Coming into Wednesday trading, shares were up 29% since the start of the Iran War, despite higher jet fuel prices. Shares of United, Alaska, JetBlue, American Airlines, and Southwest Airlines were down an average of 10%. Over the past five years, Delta stock was up almost 100%. Only United shares have outperformed. The average return of the other five airline stocks over that span was minus 4%.

The Starlink spat isn't impacting Delta stock significantly yet, but investors should keep an eye on the situation. Shares were down 1.5% in early trading, while the S&P 500 was up 0.5%.

Delta's choice of WiFi provider isn't likely to affect SpaceX stock. SpaceX wants to win business, of course, but it's valued at about $2 trillion (mainly because of the company's growing AI business). Delta's market value is close to $60 billion. SpaceX stock was up 1.3% in early trading.