One of Harry Styles' ex-girlfriends will be featured on his new album, Fine Line.

During a new interview on New Music Daily with Zane Lowe, the former One Direction singer revealed a former flame will appear at the end of the song "Cherry," off his highly-anticipated album, which drops on December 13. Though he didn't name who, Styles did say fans will hear this mystery woman's voice on the track.

"That was my ex-girlfriend," he told Lowe after previewing the song. "I don't know. I think it was because it got added in later on, and it felt so part of the song. It just felt like it needed it. We're friends and stuff, so I asked her if it was okay. And she was okay with it. I think she liked it."

So, who could it be? Our guess is Kendall Jenner since the two had an on-off relationship, which has spanned nearly three years, and have remained on good terms, but it could also be Taylor Swift. After all, Styles is releasing the album on the "Lover" singer's 30th birthday, so maybe he'll surprise everyone by giving his ex a little nod.

Elsewhere in the interview, the "Lights Up" hitmaker also addressed his songwriting process and how difficult it was to make an album he wanted, as well as one the world expected.

"I was feeling a lot of pressure because the last record wasn't a radio record," Styles explained. "And [producer] Tyler [Johnson] just said to me, ‘You just have to make the record that you want to make right now. That's it. There's no let me make sure this one is a commercial success, so that I can make what I want later down the road. You just have to make the record that you want to make right now.' So, then we stayed up and wrote ‘Cherry' that night."

Watch Harry Styles' full interview, below:

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