Primark has announced it is reviewing its unisex changing room policy after a shopper says she was left in tears when two men opened the curtain and walked in on her.
Charlotte Kirby said she was left shaken up by the incident in Primark's Cambridge store on Friday.
The 25-year-old uploaded a tearful video to TikTok afterwards, saying that two different men had pulled back the curtain in separate incidents while she was trying on clothes.
It comes after the chain of stores announced it would no longer have separate male and female changing rooms in any of its stores - after rolling out a trial of the change in 2019.
Instead, all customers would be allowed to try on clothes in individual cubicles alongside one another.
In a statement, Primark said: "We’ve received questions about an incident in our fitting rooms this weekend.
"We’re sorry for the customer's experience and want to ensure this doesn’t happen again.
"This is something we’ve been looking into to ensure everyone always feels safe & comfortable - we’ll share more soon."
The decision to introduce unisex changing rooms was welcomed by equality campaigners when a trial of the move was first announced in 2019 while other customers threatened to boycott the branches involved.
In her video, Ms Kirby said: "I feel really stupid being emotional about this, but I was trying on some clothes, and it was a unisex changing room which I'm really for and I love that because it makes everyone feel included.
"But twice, two men opened the curtain and walked in on me. Luckily both times I was fully clothed, but I could easily not have been. It was two different people clearly from the same group.
"There was probably 100 changing rooms available. So it wasn't like, 'Oo is someone in here or not?'"
Ms Kirby added Primark's staff were "amazing" when she told them of her traumatic experience.
She added: "They were really really good about it.
"They have walked me back to my car because I was scared. Apparently it's not the first time it's happened. Security are watching back the tapes and trying to find who it is. I just want to say to people please be careful and if you go in the changing room try not to go on your own.
"I would never do that again, I would rather take it home, try it on and get it back and get it refunded.
"Stay safe."
Ms Kirby wrote alongside her video: "Please be aware/spread the word and stay safe girls.
"Don’t go in changing rooms alone. This never even crossed my mind when I went into a unisex changing room.
"Thank you @primark for dealing with this so well. I know worst things could have happened but I still feel very shaken up."