John Mayer recently opened up about his feelings toward his 2013 duet with Katy Perry, “Who You Love,” a track that emerged during their on-again, off-again relationship, which lasted about three years before their final split in 2015.

The “Gravity” singer delved into his perspective on the song during his appearance on Watch What Happens Live With Andy Cohen After Show on October 2. When asked to identify his least favorite album, Mayer chose Paradise Valley. While he expressed fondness for some of the album’s tracks, he admitted it held less personal significance compared to his other works. Despite this, host Andy Cohen specifically praised “Who You Love,” and Mayer agreed it stood out as a strong piece of music.

“Isn’t that great?” Mayer said, reflecting on the song. “I’m glad we did that.”

He went on to describe the track as an “early Sob Rock prototype,” referring to his later album Sob Rock, which leans heavily into retro influences. Mayer explained the mindset he had while creating “Who You Love.”

“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?'” Mayer shared. “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.”

The Grammy winner also took a moment to praise Perry’s performance on the song, acknowledging her talent and the energy she brought to the project.

“But I listen to that every once in a while, and I go, ‘I like that song,'” he said. “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.”

Mayer and Perry first sparked dating rumors in 2012 following Perry’s divorce from Russell Brand. Over the next few years, the couple navigated a relationship marked by periods of reconciliation and separation until their ultimate breakup in 2015.

Years later, Mayer reflected on their time together in his 2017 song “Still Feel Like Your Man,” a track widely interpreted as addressing his feelings after their split.

“Who else would I be thinking about?” Mayer said during an interview with The New York Times in 2017, candidly pointing to Perry as his muse. “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.”

As Perry has since moved on—now engaged to actor Orlando Bloom and co-parenting their 3-year-old daughter Daisy Dove Bloom—Mayer’s reflections on “Who You Love” reveal a sense of nostalgia and appreciation for the musical moment they shared together.