Model Josh Kloss has accused Katy Perry of sexually assaulting him when the pair worked together in her 'Teenage Dream' video.
He says she forcibly pulled his pants and underwear away from his body at a party, showing his genitals to "a couple of her guy friends and the crowd".
At the time of publishing, Perry has not responded to the allegations, but associates and fans have rubbished the claims.
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Kloss makes the accusation as part of a lengthy statement on Instagram, posted just after the ninth anniversary of the release of 'Teenage Dream'.
"After I met Katy... she was cool and kind. When other people were around, she was cold as ice [and] even called the act of kissing me 'gross' to the entire set while filming," says Kloss.
"After the first day of shooting, Katy invited me to a strip club in Santa Barbara. I declined.
"So I saw Katy a couple times after her break up with Russell. This one time I brought a friend who was dying to meet her. It was Johnny Wujek's birthday party at Moonlight Rollerway. And when I saw her, we hugged and she was still my crush.
"But as I turned to introduce my friend, she pulled my Adidas sweats and underwear out as far as she could to show a couple of her guy friends and the crowd around us my penis. Can you imagine how pathetic and embarrassed I felt?"
Wujek is one of the people denying the claims.
"This is such bullshit," he states on Instagram.
"Katy would never do something like that. We all know about your ongoing obsession with her since the day of filming that video."
Kloss says he's made the statement as "our culture is set on proving men of power are perverse, but females with power are just as disgusting".
"So, happy anniversary to one of the most confusing, assaulting, and belittling jobs I’ve ever done... f**k this, I'm not helping her BS image another second," he continues.
It's not the first time a man has spoken out after sharing the screen with Perry.
A 19-year-old American Idol contestant named Benjamin Glaze said he'd felt "uncomfortable" after the 'Firework' singer surprised him with a kiss on the lips on the show.
He later clarified that he didn't feel sexually harassed, however.
Responding to those defending Perry, Kloss tells them to give their loyalty to Kris Jenner and Kim Kardashian instead, as they are "two women in a lot more power" that treated him "with respect".