Hi, Does Delta service Manila? If so, your friends definitely need to go with Delta. My mominlaw has the extra seat problem, so I've actually called around in the past to several airlines regarding this. Delta is the only one that I have encountered that will refund the extra seat IF there is no need for it. Say if you buy two seats and the plane is pretty empty or there's several extra seats left over, you can get your cost for the extra seat refunded. But if the plane is full and they could have sold that extra seat to a normal sized passenger, they will charge you for it. So--if you can, go Delta and try to schedule an emptier flight. Personally, I would find it torture to endure a flight sandwiched between two obese individuals. And I think that is a sort of punishment for being so large. If they weren't, then this all wouldn't be an issue.