The couple was four hours into an 11-hour flight from Los Angeles to Tokyo when the crew found an unauthorized passenger.
The crew of the All Nippon Airways flight discovered the errant passenger hours into the flight Tuesday and the jet returned to Los Angeles.
According to Ms Teigen, the passenger boarded at LAX airport with a ticket for a different airline, although this was not confirmed by authorities.
Chrissy Teigen and John Legend weren't all smiles Tuesday night. Per The Guardian, an unidentified "rogue passenger" somehow boarded the wrong plane-a la Kevin McCallister in Home Alone 2: Lost In New York-and no one noticed until everyone was hovering somewhere over the North Pacific.
The airline said it takes great pride in providing "exemplary customer service" but "failed to do so" on this flight.
After landing back at LAX, things got even more interesting and Teigen held it together by Tweeting every second of her adventure. The couple and all passengers on All Nippon Airways flight 175 spent 8 hours and 20 minutes in the sky, and Teigen tweeted through the whole thing.
It appears the mistake was the passenger in question may have been on the wrong airline entirely.
101-year-old Olivia de Havilland will not let her beef with Ryan Murphy and his Feud TV show die, and I can only dream about having as much persistence as she has after over a century on this floating shitbox.
"Taking off!" she finally tweeted early Wednesday. 150 people have been majorly inconvenienced, please, just tell me", she wrote, later adding, "They keep saying the person had a United ticket. We are on ANA. The total time for the flight to take off and return was just over eight hours. "ANA would like to express its apologies to the passengers for the inconvenience", it said. So basically the boarding pass scanner is just a beedoop machine that makes beedoop noises that register to nowhere ...