As Attitude reported, Jeff Cobb and his husband were about to board their EVA Air flight from San Francisco to Taipei and arrived early for family boarding, but were told that the airline's policy was that only one parent was allowed to take a child on the plane and the other had to wait in line. But that wasn't necessarily the case.
Jeff wrote on Twitter: "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. 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. When I met him on the plane, he said there were many other (straight) families all boarding together."
As this report explained, during their connection in Thailand with the same airline, both parents were able to board early togeher despite the "policy" of the previous flight.
A spokesperson for EVA Air responded to this incident.
"EVA Air and most especially our San Francisco International Airport team sincerely apologise to all the passengers affected by this incident. It is our policy that passengers traveling with infants can have priority boarding. The policy does not limit the number of accompanying adults or specify the relationship to the infant. This unfortunate incident was due to misunderstanding. Our San Francisco ground-handling agent understood that only one parent could board with an infant. We have apologised 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."