Jack Antonoff Laughs Out Loud at a William Bowery Poster

Jack Antonoff had no choice but to shake it off when a fan asked him to sign a poster referencing William Bowery, a.k.a. Taylor Swift’s ex-boyfriend Joe Alwyn.

The funny encounter went down during a signing event at Rough Trade Berlin on Saturday, August 31. A fan approached Antonoff, 40, with a poster in the style of the “22” shirt Swift, 34, wears during her Eras Tour and read its text aloud to him: “Who’s William Bowery anyway?”

In response, Antonoff shrugged and laughed, per an X video. The fan later shared a photo of the autograph Antonoff gave her, which included the word “folklore.”

The Grammy winner was in Berlin for a Bleachers show on Friday, August 30. According to a Reddit post, one fan in the audience held up a similar William Bowery sign during the concert, and Antonoff again laughed in response.

Related: Every Song Taylor Swift Cowrote With Joe Alwyn as William Bowery

Taylor Swift didn’t just find inspiration from Joe Alwyn during their relationship, they also collaborated on some of her songs. Alwyn was credited as a songwriter on several of Swift’s tracks throughout their relationship. He wrote under the pen name William Bowery, which Swift confirmed herself in her November 2020 documentary, Folklore: The Long Pond […]

As Swift fans know, William Bowery was the alias used by Alwyn, 33, when he collaborated with his ex-girlfriend on several tracks from her albums Folklore, Evermore and Midnights. While fans speculated that Bowery was really Alwyn, Swift didn’t confirm his identity until November 2020 when she spoke about it in the Disney+ documentary Folklore: The Long Pond Studio Sessions.

“I came in and I was like, ‘Hey, this could be really weird, and we could hate this, [but] because we’re in quarantine and there’s nothing else going on, could we just try to see what it’s like if we write this song together?’” Swift said, adding that Alwyn wrote the “entire piano part” for “Exile” on Folklore. “He was just singing it, the way that the whole first verse is … I was entranced and asked if we could keep writing that one.”

Because he is credited as a cowriter on Folklore, Alwyn also took home a Grammy in 2021 when Swift won Album of the Year for the LP, which was coproduced by Antonoff and The National’s Aaron Dessner.

While accepting the award, Swift gave a rare shout-out to her then-boyfriend. “Joe is the first person that I play every single song that I write, and I had the best time writing songs with you in quarantine,” she said at the 63rd Annual Grammy Awards in March 2021.

Despite his successful foray into songwriting, Alwyn said he didn’t foresee more music composition in his future. “It’s not a plan of mine, no,” he told Elle magazine in April 2021 when asked whether he has any interest in writing more songs.

Swift and Alwyn split in April 2023 after six years of dating. Following a brief fling with The 1975’s Matty Healy, Swift moved on with Kansas City Chiefs tight end Travis Kelce. Alwyn, meanwhile, sparked dating rumors with The Brutalist costar Emma Laird in March.