Taylor Swift confirms boyfriend Joe Alwyn co-wrote two songs from Folklore under the pseudonym William Bowery

Taylor Swift has confirmed mystery co-writer William Bowery, who is credited on her latest album Folklore, is in fact her boyfriend Joe Alwyn.

The announcement was made in her Disney+ special, Folklore: The Long Pond Studio Sessions, after fans had speculated it could be a pseudonym for the English actor, who has been dating Swift for three years.

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"There's been a lot of discussion about William Bowery and his identity because it's not a real person," the 30-year-old Grammy winner said. "So, William Bowery is Joe, as we know."

She explains to her collaborators Jack Antonoff and Aaron Dessner that the actor, 29, "plays piano beautifully, and he's always just playing and making things up and kind of creating things," including the "entire piano part" on her song 'Exile' with Bon Iver.

"He was just singing it the way that the whole first verse is and so I was entranced and asked if we could keep writing that one," Swift explained. "It was pretty obvious that it should be a duet because he's got such a low voice and it sounded really good sung down there."

READ MORE: Taylor Swift and Joe Alwyn's complete relationship timeline

The Favourite star also co-wrote Swift's song 'Betty,' telling Antonoff, 36, and Dessner, 44, that he helped write the single when she heard him singing "the entire fully formed chorus from another room."

"I was just, like, 'Hello'," she reveals in the film. "It was a step that we would never have taken because, why would we have ever written a song together?"

Swift and Alwyn have largely kept their relationship private. They've never shared pics as a couple on social media, let alone walked a red carpet together and have only been spotted in public a handful of times.

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