Katy Perry's "Teenage Dream" co-star has accused her of sexual assault, claiming she exposed his penis at a party.

Josh Kloss, the model who played her love interest in the 2010 music video, shared a lengthy Instagram post on Sunday (August 11) detailing the alleged encounter that left him feeling "pathetic and embarrassed."

He begins his message by noting how "cool and kind" Perry was when they first met, admitting he even developed a crush on her. However, her behavior confused him because she was only nice to him when others weren't around.

“When other people were around she was cold as ice even called the act of kissing me ‘gross’ to the entire set while filming,” he wrote. “After the first day of shooting, Katy invited me to a strip club in Santa Barbara. I declined and told her ‘I have to go back to [the] hotel and rest because this job is all I have right now."

"So I saw Katy a couple [of] times after her break up with Russel [Brand]. This one time I brought a friend who was dying to meet her. It was Johnny Wujek [Perry's creative director]'s birthday party," Kloss continued. "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?" he added.

Kloss then goes on to say he was only paid $650 for his work and that the only reason he's speaking out now — nearly 10 years after the "Teenage Dream" music was released — is because "our culture is set on proving men of power are perverse, but "females with power are just as disgusting."

Despite the allegations though, he did say Perry is an "amazing leader" and her songs serve as "great empowering anthems." He claims he just can't support her "bs image another second."

Read Josh Kloss' full Instagram post, below:

Perry has not yet responded to Kloss’ accusations, but we'll update this post if she does.