Lots of people choose casual attire as their go-to for a long flight. But for two girls at Denver International Airport on Sunday, that choice almost kept them from being able to fly at all.

Two passengers reportedly were attempting to board a United Airlines flight to Minneapolis on Sunday when the gate agent told them they had to change their clothes or they wouldn’t be allowed on the plane.

According to Twitter user Shannon Watts, who witnessed the interaction, the agent took issue with the girl’s leggings. Twitter erupted after Watts sent a three-part tweet of her account to United.

In a statement posted Monday, United said the passengers in question were “pass riders,” which are friends or relatives of its employees, and receive free or discounted rates on flights.

“The passengers this morning were United pass riders and not in compliance with our dress code for company benefit travel,” United said. “We regularly remind our employees that when they place a family member or friend on a flight for free as a standby passenger, they need to follow our dress code.”

Although United did specify Sunday on Twitter the girls were “pass riders,” it initially didn’t say they needed to adhere to a different dress code than other passengers. Instead, it justified the agent’s decision by referring people to Rule 21 of its contract of carriage, which says employees can remove passengers “who are barefoot or not properly clothed.”

In a later tweet, United shed a bit more light on how the customers violated the “pass riders” rules.

While United was scrambling to conduct damage control on Twitter, its competitor used the situation as an opportunity to cheekily market itself as a more accepting airline.

If you ask us, flying any airline should mean comfort. After all, when you’re in a metal tube in the sky, the last thing you want to worry about is being uncomfortable.

Thumbnail photo via United Airlines