She claimed that she had been waiting for the American Airlines’ Texas-Miami flight at Dallas/Fort Worth International Airport when flight attendants told her that her outfit was inappropriate.
She took to Instagram to express her outrage, writing that she had been told that she was "naked" and that her choice of outfit "disturbed other families" at the airport.
She tagged American Airlines in the Instagram post and posted a picture of the outfit in question, which included a brown crop cop, tiny denim shorts, trainers, and a white shirt tied round her waist.
She captioned the post: "I am an athlete, and now I have to wait here until the morning. I like to wear feminine clothes that reveal my femininity, but I never dress in a way that will offend anyone. I'm mature and civilized enough to know what I can and cannot wear. I don't deserve to be treated like the worst person in the world for wearing denim shorts. What separates us from animals if humans can't control even their most primitive impulses?"
Deniz, who has been a personal trainer for seven years and was the first non-US citizen to win the US National Bikini Fitness Competition this year, received support from her followers, who expressed their outrage on her behalf.
One person commented: "It is 2021, and there is still a dress code you have to follow to board a plane, of course, only if you are a woman. This is ridiculous."
A second person wrote: "Teach society to respect women, rather than telling women what to wear or what to do."
A spokesperson for the airline responded to the matter: "On July 8, American Airlines denied boarding for a customer travelling from Dallas-Fort Worth to Miami. As stated in the conditions of carriage, all customers must dress appropriately and offensive clothing isn’t permitted onboard our flights. The customer was advised of our policy and was rebooked on a subsequent flight. The customer has since arrived in Miami."