NEW YORK (AP) — Don’t mess with our stretch, United Airlines, or risk the wrath of leggings lovers.

The social media matter of The Kids in Leggings vs. United snapped to the surface Sunday. That’s when one Shannon Watts said on Twitter she had witnessed a gate agent refusing to let two girls board a flight from Denver to Minneapolis because of their leggings.

The incident, with United’s Twitter account chiming in, rolled right on through to Monday, prompting debate on whether leggings are “pants.” That especially goes for women and girls and whether the United dress code for people on standby who are availing themselves of free passes, as these girls were, has perhaps not kept pace with the elevation of stretchy pants from gym and yoga garb to more broadly acceptable.

Or are leggings more like women’s stockings and therefore inappropriate for plane travel when worn as pants, as one Facebook user argued — or is this a better comparison, as suggested by another: “It’s like going to a baseball game on a player’s tickets and doing something against the rules, right?”

Besides, some on social media said, many airlines adhere to the same standards for flying on this type of freebie.

“Casual attire is allowed as long as it looks neat and is in good taste for the local environment,” tweeted the United account in response to one angry leggings defender Watts whipped up Sunday.

“United shall have the right to refuse passengers who are not properly clothed via our Contract of Carriage,” another tweet from United explained.

The policy for family and friends on passes is different from that for the rest of us paying folk. For United, it seems in this case to be about the stretchy fabric.

American Airlines, for paying passengers, reserves the right to bar you if you are clothed in a manner that would “cause discomfort or offense to other passengers or are barefoot.”

But American has a separate policy for employees and their guests: They’re prohibited from wearing clothes that are “torn, dirty, frayed or overly revealing.” If an employee or guest is traveling in first or business class, he or she can’t wear shorts, flip-flops or baseball caps, under that American dress code.

The point for some airline insiders, however, is different. Some of them contend anybody eligible for the types of free passage afforded the girls on Sunday is well aware of dress code restrictions, however silly they may seem from the outside.

Kristin Taylor, in tony Greenwich, Connecticut, is a leggings lover and sees them everywhere in her world. She’s also a psychologist and stay-at-home mom to two of three sons, “so no leggings…