That’s a stretch.

United barred two tween girls from a flight Sunday because they were wearing leggings – and thanks to Tweets blasting the airline led by Patricia Arquette, Chrissy Teigen and William Shatner, the controversy took off.

“Star Trek” star Shatner shared a snap of himself on the Starship Enterprise dressed in the fictional crew’s signature spandex uniforms.

The Spandex squabble took flight after a fellow passenger at Denver International Airport noticed two visibly upset girls turned away from the gate next to hers. Shannon Watts, founder of the anti-gun violence group Moms Demand Action, said one was wearing gray leggings. Other flyers waiting to board were frantically pulling dresses over their own daughters’ stretch pants to fit the dress code. Meanwhile, men with shorts above the knee weren’t being turned away.

“Apparently @united is policing the clothing of women and girls,” Watts tweeted to her more than 34,000 followers, kick-starting the firestorm.

The airline’s initial response, that it “shall have the right to refuse passengers who are not properly clothed,” further infuriated consumers.

Now it turns out, the two girls United turned away are part of a free company travel program, which does have a stricter dress code than regular passengers because those getting the perks are representing the airline.

Problem is, they didn’t tweet that out in the first place. “They were on travel passes, which is a whole different story. We’re not talking about 98% of the traveling public,” said Seth Kaplan, industry expert and editor of Airline Weekly. “That’s all United had to say. They didn’t handle this well.”

The airline tried explaining itself in statement later on Sunday.  “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,” they wrote.

And that dress code calls out “form-fitting lycra/spandex tops, pants and dresses,” crop tops and “any attire that is provocative, inappropriately revealing, or see-through clothing,” which critics say disproportionately polices women’s wear.

But this doesn’t take comfort or common sense into account. Casual wear is here to stay. While overall apparel sales rose only 3% last year, athleisure sales of leggings, shorts and tops jumped 11% and made $45.9 billion last year.

The airline added, “To our regular customers, your leggings are welcome.”

But the damage was done.

This harks back to a similar dust-up last year, when JetBlue turned away a burlesque dancer trying to fly out of Boston because a gate attendant said her shorts were too short. The customer offered to tie her jacket around her waist or borrow a blanket, but she still missed her flight.

A woman was also booted from a Spirit Airways flight in January for baring too much cleavage.

The airlines haven’t answered calls for comment yet.

Now, flyer beware: There are vague dress and hygiene codes buried in an airline’s “conduct of carriage” rules that you may not be aware of. One cannot fly most airlines barefoot, for example. DeltaJetBlue and other airlines can also turn away passengers with a “malodorous condition,” so you could be banned from your flight if they think you stink.

The problem is that gate agents working for each airline have discretion in deciding who is presentable to fly, Kaplan explains.

“There is some judgment involved … and you can’t help the fact that people are going to have their own unconscious thoughts about how people present themselves,” he said.

While he doesn’t condone what’s right or wrong, he suggests flyers play it safe. “Yes, this isn’t the old days where people dress up to fly,” he said, “but if your goal is to just get to where you are going, don’t wear something vulgar or offensive or extremely provocative that might not fit in a family setting.”

Or carry a sweater or cover up in your carry-on, just in case you’re stopped by the airport fashion police.