If they have to ask for an extension on the lap belt to get it to buckle then they should be charged for an additional seat. These people don't have to sit next to themselves. I must be one unfortunate dude because I seem to always get seated next to someone who is a twinkie shy of 350 lb. and spilling over into my seat. I can't put my arm on the arm rest because their side is covering it.
Their obesity is their problem. But it shouldn't be imposed on me!