Katy Perry ranks John Mayer as her best lover to date

Katy Perry has declared John Mayer as her best lover to date after she was asked to rank the rocker alongside Orlando Bloom and DJ Diplo.

The Roar hitmaker has been live-streaming her life on her YouTube channel since Thursday night (09Jun17) to celebrate Friday's (09Jun17) release of her new album, Witness, and she has been visited at her Los Angeles hideout by a string of famous friends.

On Sunday morning (11Jun17), talk show host James Corden joined Katy for a daring round of truth or dare, in which they each had to answer random questions or tackle a strange snack, which featured delicacies like beef tongue and oddities such as bird saliva.

Katy, who was dressed in her pajamas, was quizzed about her love life during the entertaining session, causing her to cringe as she loudly protested the task.

"From best to worst in bed, working on the notion that they're all good, rank John Mayer, Diplo and Orlando Bloom," Corden said, before quipping, "Diplo's in third, we know that... I'm not being bad, it's just the other two are clearly exceptional!"

"Oh, f**k! No! I will not do that!" exclaimed an embarrassed Katy. "They are all amazing lovers and I would have sex with all of them after I get out of this place!"

After some encouragement from Corden, Katy reluctantly agreed hitmaking producer Diplo, who she was briefly linked to in 2014, would be third, behind British actor Orlando, who she split from in February (17) after a year-long romance.

The singer, who was previously married to British comedian Russell Brand, then admitted Mayer would take first place. The stars enjoyed an on/off relationship for three years until calling it quits for good in late 2015.

And Katy didn't stop her kiss-and-tell there, the 32-year-old confessed another singer, Josh Groban, was the one who got away after they were rumored to have dated in 2009.

Groban touched on the relationship in a 2013 interview with Details magazine, revealing they are "very good friends" who "might have skated on the line of dating", although things never quite turned romantic.