As flying goes, the only thing more uncomfortable than sitting next to a couple having a spat on an airplane, Maury Rogoff learned, is sitting between that couple, especially when one partner prefers bare feet.
Rogoff, who owns a public relations firm with offices in New York and Florida and travels frequently, discovered what a growing number of travellers now know: The middle seat has become the third rail of flying and it is getting harder to avoid.
As planes fly at record capacity and new cabin configurations squeeze in ever more passengers, airlines are, intentionally or not, nudging fliers into paying extra to avoid drawing the proverbial short straw.
"I was literally in the middle of their argument," Rogoff said. "It was just that awful." Her discomfort was magnified when the husband kicked off his shoes and crossed his legs, thrusting a bare foot into Rogoff's space.
Her entreaties with his wife to swap seats fell on deaf ears. "Of course she had no interest because it was middle, and because it was a smelly foot," Rogoff said.
For travellers like Rogoff, airlines are making it harder than ever on domestic and international flights to avoid the middle seat based on luck alone.
Southwest, which does not assign seats, raised the price of an early-boarding pass to $US15 from $US12.50 last month. For those who do not pay up, it is a mad rush to secure an earlier boarding group when online check-in opens 24 hours before the flight.
Delta Air Lines' Basic Economy fare, introduced last year, does not allow seat assignments to be made until after check-in when higher-paying customers have had a chance to claim window and aisle seats. Basic Economy is also available in about 50 markets internationally, the airline said.
American Airlines and United Airlines plan to introduce similar fares this year. Neither would confirm whether selecting a seat would be one of the perks eliminated, but one airline analyst said it was likely, given the competition legacy airlines face from low-fare carriers.
See also: When an aisle seat is not the aisle seat
"It's a way to compete," said Max Rayner, a partner at Hudson Crossing, a consulting firm in New York. "If you want to go at premium times, there will be far fewer seats available at the lower end of prices."
Rayner suggested that this shift in pricing models wasn't necessarily a bad thing, saying it could be a boon for the most price-sensitive customers. "You can think of it actually as opening up choice," he said. "You just want basic transportation sure, here it is."
But the crunch has left some travellers taking extreme measures to avoid getting stuck in the middle.
Fliers said they have offered fellow travellers money or drinks to switch seats, paid the fee to upgrade to a premium or exit row, feigned illness or switched flights. Some travellers even report buying two seats, just to have an empty one next to them. It is cheaper than business class.
Dr. Sachin Shridharani, a plastic surgeon in New York, found himself on an overbooked flight back from San Diego, and a middle seat was the only one available.
"I told them I'd be willing to take another flight," he said. "I'll pretty much do just about anything to avoid sitting in that notorious, infamous middle seat."
The trade-off was to wait in the airport for four hours, but Shridharani said it was worth it so he could work on the way home. "You can't have someone looking over your shoulder," he said.
See also: Best and worst plane seats
In the end, analysts say, airlines are selling a form of real estate, but they are trading in square inches, not square feet.
"People buy work space; that's really what they buy on board," said Robert W. Mann Jr., an airline industry consultant. "Some of those configurations may not give you enough room, for example, to take out a laptop and use it productively."
One carrier, though, has tried to address the issue. Frontier Airlines recently installed new seats on its Airbus A319 and A320 planes, with the middle seats about an inch wider than the window and aisle seats.
But for most passengers, the tight squeeze continues, and business travellers say counting on their frequent flier status to avoid the middle seat is no longer a sure thing.
"You can't show up at the airport hoping to talk your way into an upgrade," said Mark Jeffries, a corporate speaker and author. "You don't see free seats anymore."
Jeffries said he sometimes buys two seats - a window or aisle, and a middle. It's cheaper than buying a business- or first-class ticket on a legacy carrier, he said.
"We find that people will pay for premium economy or any kind of seat assignment if they're travelling solo to avoid the middle seat," said Julia Douglas, owner and president of Jet Set World Travel in Chicago. Some travellers will spend hundreds of dollars more, she added.
Another approach is to appeal to another traveller. "There have been instances where I've bought someone an upgrade," said Michael Winston, who used to travel once or twice a week while working in management consulting. At times, he said, he had resorted to bargaining with seatmates to avoid the middle seat.
It is not an uncommon transaction, frequent travellers say, with cash, upgrades and cocktails all serving as forms of currency. But that is assuming that the seats are available.
Last year, airline capacity again hit a record high, just shy of 85 per cent, meaning that a lot of flights are full.
And that leaves flight attendants and travel agents acting as de facto referees for games of midair musical chairs. The excuses passengers use to avoid the middle seat are many, they say.
"Long legs is always one," Douglas said. She then listed the most common complaints: claustrophobia, a need for frequent trips to the bathroom, flight-induced panic attacks and a penchant for airsickness.
"I don't know if any of them are truly medically founded," she said. "I just think it's anxiety about being in that middle seat."
Of all the excuses, genuine or exaggerated, the one that seems most effective is the threat of gastrointestinal distress.
William Bauer, who travels frequently as an executive at a manufacturer of leather goods, said that hinting at a medical need for quick access to the bathroom usually prompted either gate agents or fellow passengers to make the switch for him.
"Make it clear that you need that aisle seat. Really convey a compelling sense of urgency," he said. "Thus far, I've never been rejected."
On one recent flight, though, the tables were turned when Bauer found himself on the receiving end of a plea to swap seats on a cross-country, red-eye flight.
"There was a woman I gave up my aisle seat for because she cried," he said. "If you cry, you win."
The New York Times