An empty class after a physics lesson. A room full of pink and blue balloons. But then you start noticing the details. The dildo on the wardrobe. The high heels and panties on the floor.

There’s an unoccupied first-class seat next to you. After takeoff, a passenger who paid $800 for a main-cabin seat decides to sit in the empty first-class seat.

Look, some of us have skipped class here and there for whatever reason. But it's pretty bad when everyone does the same too. And in the first week. Adrian Raftery, an associate professor at ...

But for any passenger, generally, airlines opt to keep these rows empty—even if it makes virtually zero difference to their bottom line. Here’s the deal: In the eyes of airlines, it’s stealing.