Alaska Airlines is apologizing for an overbooking situation in which a gay couple was asked to relinquish their seats to a heterosexual pair.

"We mistakenly booked two people in one seat. We are deeply sorry for the situation, and are investigating the details," the carrier said in a statement, adding that it has a "zero-tolerance policy for discrimination of any kind."

The apology came after Los Angeles restaurant owner David Cooley took to Facebook on Sunday to vent about his experience on an Alaska Airlines flight bound from New York's John F. Kennedy International Airport to Los Angeles International Airport.

"After my traveling companion and I had been seated in our assigned seats for a while, we were approached by the flight attendant and my companion was asked to move from his premium seat to coach, so a couple could sit together. I explained that we were a couple and wanted to sit together. He was given a choice to either give up the premium seat and move to coach or get off the plane," Cooley, owner of the iconic LA gay bar The Abbey wrote in a post shared more 2,100 times.

 
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"We could not bear the feeling of humiliation for an entire cross-country flight and left the plane," Cooley added. "I cannot believe that an airline in this day and age would give a straight couple preferential treatment over a gay couple and go so far as to ask us to leave."

In acknowledging its error, Alaska Airlines said the gate agents involved in the incident did not realize the men were a couple.

Cooley ended his Facebook post calling on LGBT people to boycott Alaska Airlines.

"Thank you to Delta Air Lines for getting us home safe," he wrote. "If you are an #LGBT person, please spend your travel dollars with an LGBT friendly airline like Delta."

Federal rules allow carriers to set their own criteria for picking passengers to bump, but the practice can be costly, both in damage to an airline's reputation and in compensating those compelled to give up their seats. An analysis of government aviation data last year found passengers bumped from Alaska Airlines flight received the highest average compensation of $1,605.

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