The 'Mars' hitmaker is a huge fan of "rock star” Katy, 36, and especially her songs such as 2008's 'I Kissed A Girl', which is regarded by many as one of the first songs to promote LGBTQ+ awareness in pop.
Speaking to the Daily Star newspaper's Wired column, the Doncaster rocker - who prefers not to label his sexuality but is "probably pansexual" - said: "I love Katy Perry and she is such a rock star, she really is.
"Especially in the beginning with 'California Gurls' and 'I Kissed A Girl' - all that stuff was so punk rock to me.
"I don't know about you but I don't remember anyone else at that time doing anything like that."
On Katy's influence on 'Cotton Candy' from his latest album, 'Weird!', he said: "I just wanted a b****-to-the-wall song about sex, sexual liberation, fluidity, and talk about everyone's ever evolving idea of sexuality."
The 23-year-old singer also recalled the time he bumped into Katy and her fiance Orlando Bloom at Coachella festival while he was "off his t***".
He said: "I met Katy Perry off my t*** at Coachella and I was like, 'F*** that is Katy Perry?'
"I was with my ex-girlfriend and it was a bizarre experience.
"I met Orlando Bloom too and I was like, 'Wow, f***, you're in 'Pirates of the Caribbean' mate, you are f***** sick.'
"Being at Coachella with Katy Perry and Orlando Bloom off my t*** was f****** insane and I was like, 'Right, OK, I can't wait to tell the guys in Norton Working Men's Club about this.'"
Elsewhere, the 'Loner' star admitted that despite his chart success, with his second album topping the Official UK Chart, that's not why he got into music.
He added: "I just wanted to tell the truth and help people figure out their identity and gender, and figuring out drugs, love, heartbreak, depression, love loss, f****** everything."