United Airlines says it refused to allow two girls to get on a Sunday morning flight from Denver to Minneapolis because they poorly represented the airline.

The girls, traveling under a pass granted to airline employees, were wearing skin-tight leggings.

Shannon Watts, who was waiting to board a flight to Mexico, took to Twitter after seeing the family “in a panic” over being denied boarding.

3) Gate agent for flt 215 at 7:55. Said she doesn't make the rules, just follows them. I guess @united not letting women wear athletic wear?

— Shannon Watts (@shannonrwatts) March 26, 2017

The girls put on dresses and took a later flight.

“I have five kids; four of them are women,” Watts told Teen Vogue. “They wear yoga pants all of the time when flying. I think this policy is arbitrary and sexist. It singles out women for their clothing and sexualizes little girls.”

That’s not how United sees it. Jonathan Guerin, a spokesman for United, says leggings violate the company policy on attire for “pass travelers,” family and friends of employees who travel for free on a standby basis.

“It’s not that we want our standby travelers to come in wearing a suit and tie or that sort of thing,” he tells the Times. “We want people to be comfortable when they travel as long as it’s neat and in good taste for that environment.”

“The girl pulled a dress on,” Watts told the New York Times. “But please keep in mind that the dad had on shorts that did not hit his knee — they stopped maybe two or three inches above his knee — and there was no issue with that.”

Twitter responded harshly to the incident but United was having none of it.

@united Do U understand U have just made at least half UR customers very unhappy?

— Patricia Arquette (@PattyArquette) March 26, 2017

It won’t mollify Twitter, but United has a point. Dress codes aren’t unusual for people who represent a business. And, as BuzzFeed points out, leggings can be problematic in a way that shorts are not.

Plus, if you’re flying on the airline’s dime, is proper attire too much to ask?

Is it a sexist policy? We won’t know for sure until a man tries to fly wearing leggings. Please, no.

If we could only go back to dressing up to fly.

Related: 12 Leggings Problems Every Woman Understands (Cosmopolitan)

Source: MPR