Katy Perry said she jokes with boyfriend John Mayer about donating his brain to science as he’s “literally a genius” according to the star.

Perry told Billboard: “He literally is a genius, as is evident from his song writing.

"I always tell him, ‘Darling, you know I’m going to have to give your mind to science after you’ve passed, because we’re going to have to understand how all these sparks work’.

“We’ll be in bed, and he’ll be doing the crossword puzzle. Every night, he tries to finish it in under 10 minutes. When he puts his mind to something, he really gets it done very well. I always ask for his help.”

Mayer and Perry have been working together musically lately too, with a duet, Who You Love, on his latest album Paradise Valley and a co-write song credit on Perry’s song Spiritual, which will appear on her upcoming album PRISM. He also plays the guitar on her track It Takes Two.