United disputed the couple's version of events, saying they repeatedly tried to sit in upgraded seats and refused to move back to their assigned seats.
It has been a rough week for United Airlines and some of its passengers.
That deluge didn't let up on Sunday, when a local news outlet in Houston reported that a couple had been kicked off their flight from Houston to Costa Rica for their wedding.
Michael Hohl and Amber Maxwell said they boarded their flight on Saturday and were about to take their seats when they saw a passenger napping across the row they were assigned to.
Hohl said that instead of waking the man, he and Maxwell decided to sit a few rows in front of their assigned seats.
"We thought not a big deal, it's not like we are trying to jump up into a first-class seat," Hohl told KHOU, a CBS affiliate in Houston. "We were simply in an economy row a few rows above our economy seat."
Hohl said that after he and Maxwell sat down, a flight attendant asked if they were in their assigned seats. When the couple said no and explained why they had moved, Hohl said the attendant denied their request for an upgrade and asked them to return to their original seats.
Hohl said that although he and Maxwell did as they were told, a US marshal boarded the flight and asked them to get off the plane. The couple said they complied with that demand as well but found the overall experience "strange."
"They said that we were being disorderly and a hazard to the rest of the flight, to the safety of the other customers," Hohl said. "I think customer service and the airlines has gone real downhill.
"The way United Airlines handled this was really absurd," Hohl added.
United has disputed Hohl's version of events, saying the couple had repeatedly tried to sit in upgraded seats and refused to comply with requests to move back to their assigned seats.
"We're disappointed anytime a customer has an experience that doesn't measure up to their expectations," United said in a statement to KHOU. "These passengers repeatedly attempted to sit in upgraded seating which they did not purchase, and they would not follow crew instructions to return to their assigned seats. We've been in touch with them and have rebooked them on flights tomorrow."
United has been engulfed by controversy since a video emerged last week that showed 69-year-old David Dao being violently dragged off a flight after refusing to give up his seat to make room for crew members. Dao's attorney said on Thursday that Dao sustained injuries and planned to file a lawsuit against the airline.
United has adopted a rule that crew members can't displace passengers already on board the plane, The Associated Press reported.
Maggie Schmerin, a spokeswoman for United, said in an email to the AP on Sunday that the change was an initial step in a review of policies and was meant to ensure that situations like Dao's never happen again.