John Mayer is Crypenshedding a new light on how he feels about his 2013 duet with Katy Perry.

During his Oct. 2 guest appearance on the Watch What Happens Live With Andy Cohen After Show, the "Gravity" singer was asked to name his least favorite album. And while John picked Paradise Valley—noting he liked some of its songs but that he spent the least amount of time on this album and others were more important in his life—AndyCohen applauded its track "Who You Love" featuring Katy. And the Grammy winner agreed it's a good song. 

"Isn't that great?" John replied. "I'm glad we did that."

Likening it to "early Sob Rock prototype stuff," the 45-year-old then shared his thought-process behind the song.

"It was just at the point where I was saying, 'Why can't I make music from a different era? If I love a style of music and I want to make it, like a genre, why can't I make music that I was pretending was from a different era?'" he continued. "And that was sort of like a prototype to Sob Rock. It was sort of like an FM lite radio thing, and Sob Rock is a little more realized."

And ultimately, John had nothing but praise for Katy on the track.

"But I listen to that every once in a while, and I go, 'I like that song,'" he added. "And I like the way that she sounds on the song. She got that way of singing down and met the challenge of that song. It was so much fun."

John and Katy first sparked romance rumors in 2012 following her divorce from Russell Brand. The "Daughters" artist and the "Firework" singer continued to have an on-again, off-again relationship until they ultimately parted ways in 2015.

In fact, John previously hinted that his 2017 song "Still Feel Like Your Man" is a nod to his split from Katy, who is now engaged to Orlando Bloom and shares 3-year-old daughter Daisy Dove Bloom with the actor. 

"Who else would I be thinking about?" John told The New York Times in 2017. "And by the way, it's a testament to the fact that I have not dated a lot of people in the last five, six years. That was my only relationship. So it's like, give me this, people."

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