Alaska Airlines has apologised to a gay couple after one of them was asked to give up his seat to allow a straight couple to sit together.
Los Angeles restaurant owner David Cooley said his travelling companion was asked to give up his premium seat and sit in the economy section.
Despite explaining they were a couple, they were given a choice of moving or getting off the plane - which they did.
The airline said it had a "zero-tolerance policy for discrimination".
In a post on Facebook, Mr Cooley said he had "never been so discriminated against while travelling before".
After his experience on the New York to Los Angeles flight, he said he would never fly with Alaska Airlines again.
In a statement, Alaska Airlines said: "This unfortunate incident was caused by a seating error, compounded by a full flight and a crew seeking an on-time departure, and nothing more than that.
"It's our policy to keep all families seated together whenever possible; that didn't happen here and we are deeply sorry for the situation.
"We've reached out to Mr Cooley to offer our sincere apologies for what happened and we are seeking to make it right."