An EVA Airways passenger flight, owned by the Evergreen Group, taxis on a runway at Taoyuan International Airport, northern Taiwan, March 14, 2016. REUTERS/Tyrone Siu

A gay couple claimed they were separated during boarding while straight families were allowed to board the plane together. Jeff Cobb and his husband were flying from San Francisco to Taipei, Taiwan, with their 19-month-old child during the incident.

The couple on Sept. 1 joined the priority boarding queue for EVA Air flight but were told that only one parent was eligible to board the plane early. Cobb said he was "disappointed" as the airline discriminated against them.

“My husband and I were told only one of us could join our 19-month-old in the family boarding group of EVA Air 27 from SFO on 9/1/18," Cobb wrote on Twitter. “I explained we were both the fathers of the child, and they said it was their policy that only one parent can board and the other has to wait in the normal line. Not having flown EVA before, I accepted it and let my husband and child go while I boarded later.”

However, when Cobb eventually boarded, his husband said the policy was not applicable for heterosexual couples.

“When I met him on the plane, he said there were many other (straight) families all boarding together,” Cobb said. “I’m very disappointed that the EVA ground staff at SFO thinks it’s OK to separate same-sex families during boarding. I will definitely not be flying this airline again after this incident.”

In a statement on Tuesday, EVA Air apologized and described the incident as a “misunderstanding.”

“EVA Air and most especially our San Francisco International Airport team sincerely apologize to all the passengers affected by this incident. It is our policy that passengers traveling with infants can have priority boarding," a representative said.

“The policy does not limit the number of accompanying adults or specify the relationship to the infant. This unfortunate incident was due to misunderstanding," the statement read. “Our San Francisco ground-handling agent understood that only one parent could board with an infant. We have apologized to our passengers and reminded our airport staff and agents about our priority boarding policy so that we can prevent this kind of incident from happening again.”

In another incident, an Alaska Airlines flight attendant in July asked a gay man to give up his seat next to his partner so a straight couple could sit together.

“We could not bear the feeling of humiliation for an entire cross-country flight and left the plane,” David Cooley said. “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.”

The airline later apologized to the couple, saying the company would offer to refund his ticket and was “deeply sorry for the situation and did not intend to make Mr. Cooley and his partner feel uncomfortable in any way.”

A 2017 survey from the Center for American Progress shows that more than 36 percent of LGBT people hid personal relationships for fear of discrimination.