Twitter flipped its lid yesterday (March 26th) after it was reported that United Airlines refused to let teenage girls board a flight because they were wearing leggings. The teens and a 10-year-old girl who was also wearing leggings were set to get on a flight from Denver to Minneapolis when a gate agent stopped them. The youngest girl was eventually allowed to board after a putting a dress over the leggings. but the teens had to take a later flight after changing their outfits. United explained that the denied fliers were using an employee's flight benefits, and employees and any friends or family flying on their passes have to follow a dress code since they are representing the airline. But for regular passengers, there is no ban against wearing leggings. That still didn't mollify some people on Twitter, who said the policy was still sexist. Business Insider got hold of a United email about travel attire for employee pass holders, and it said unacceptable clothing includes, quote, "beach-type rubber flip flops, slippers, anything with holes or tears, anything that reveals your midriff or undergarments and form-fitting Lycra or spandex pants, such as leggings."