Katy Perry has revealed the secret behind snaring fiance Russell Brand.

The 25-year-old pop singer got engaged to the former lothario after making him wait to sleep with her.

“Can you imagine the horrible feeling he had, when he was used to getting everything he wanted?” she said in an interview with Esquire magazine.

“I was like, ‘You’ve met your match.'”

Katy, who introduced herself to 35-year-old Russell by throwing a plastic bottle at his head, added: “He was a heroin addict, now he’s not. He basically used to be a professional prostitute, now he’s not.

“I always needed someone stronger than me. And I’m a ****ing strong elephant of a woman. When we have an argument, he knows I’m not going to throw my hands up and say, ‘OK, you win’.

“He really tries. He’s a wonderful learner.”