It’s every traveler’s worst nightmare.

You settle in for a long flight. You try to get comfortable. Get your complimentary ginger ale. Put your headphones in. And then, it happens.

You see toes. The passenger behind you has officially broken the sacred, cardinal rule of air travel: Never, ever put your bare feet up on a flight.

Why is this such a preciously held rule amongst passengers the world over? Well, first off, it’s potentially unsanitary and a bit gross. No matter how well pedicures your feet may be, tracking in germs and dust from walking through an airport terminal is the last thing you want in your face for hours on end.

And second, it’s just rude.

This is what happened to YouTube poster Jasmine Mays, and her expression says it all. Her shock and horror is the natural reaction when our precious window seat is invaded by another passenger’s bare feet.

If she could run screaming into the night, she probably would. And we don’t blame her.

Hopefully she summoned the courage to say something to the foot-intruder.