After Katy Perry celebrated her 15th anniversary of her breakout album One of the Boys (2008), Halsey was quick to jump in on how the California Gurls singer changed their life. From there, Halsey's inspiration from Perry grew, per People.

Katy Perry wrote on Instagram thanking her fans: “She may be a young teen but has always had a bit of an attitude,” Perry wrote. “Thank you to all the KCs who have stuck around since the Warped and Hello Katy days… tbh I still think of myself as One of the Boys.”

Halsey was quick to jump in on the post, commenting: “Katy I saw you stage dive and run around with your parasol at Warped!!! I must have been 13 or 14 years old,” the singer said. “That day changed my life! For real!”

The two of them have regularly supported each other. Back in June 2022, Halsey vocalized their opinion on abortion rights. “The ‘people pay to see you sing not hear your views’ argument is so dumb,” Halsey tweeted. “No, you paid to see me use a stage as a form of expression in the manner that I choose. Sorry, you lack the critical thinking to realize that the rhetorical power of music doesn’t always serve your escapism.”

Perry retweeted the message, adding, “Go off Queen.”

But it's clear that Halsey deeply admires the Teenage Dream singer. “Anyone who's trying to make a perfect pop album is wasting their time anyway because Katy already did it with Teenage Dream,” they said. “No one ever needs to do it ever again… If you're trying to make a perfect pop album, you're just trying to make Teenage Dream again.”