Taylor Swift and Jack Antonoff have collaborated for years. After meeting and becoming friendly, she recruited him as her producer on her pop cross-over album, 1989. Antonoff thinks quite highly of Swift, and she returns the sentiment. She went so far as to say that she wouldn’t trust a person who didn’t like Antonoff.

Taylor Swift has a high opinion of Jack Antonoff

Swift said that when she worked with Antonoff, the music flowed naturally and with ease. This made him an ideal creative partner for her.

“Sometimes he sits at the piano and we both just start ad-libbing and the song seems to create itself,” she told The New York Times. “His excitement and exuberance about writing songs is contagious.”

She found Antonoff so talented and likable that she couldn’t trust a person who disliked him. She ultimately didn’t think many people had negative feelings about him, though.

“He’s an absolute joy. That’s why everyone loves him,” she said. “I personally wouldn’t trust someone who didn’t.”

Jack Antonoff said Taylor Swift completely changed his career

In 2014, Antonoff posted about Swift’s song “Out of the Woods” on his Instagram account. In the caption, he wrote glowingly about her.

“[I] will one day write an essay on the different production I used on the song + how much working with taylor on it has meant to me,” he wrote. “she’s a wonderful artist.”

Antonoff’s collaboration with Swift was particularly meaningful for him because she was the first artist who allowed him to produce an album.

“I’d been trying to produce for a while, but there was always some industry herb going, ‘That’s cute, but that’s not your lane,’” he told The New Yorker. “Taylor was the first person with the stature to go, ‘I like the way this sounds, I’m putting it on my album’ — and then, suddenly, I was allowed to be a producer.”

She wrote a song about him

Swift also saw Antonoff’s former partner, Lena Dunham, as a close friend. She adored the show Girls and reached out after she saw Dunham praising her on social media. Swift wrote the song “You Are in Love” about the couple. It included the line “You are my best friend,” which Swift said was directly inspired by Antonoff and Dunham.

“I’ve never had that, so I wrote that song about things that Lena has told me about her and Jack,” Swift told Elle in 2015. “That’s just basically stuff she’s told me.”

She said she saw the beauty and challenges in that type of relationship.

“I think that that kind of relationship — God, it sounds like it would just be so beautiful—would also be hard,” she said. “It would also be mundane at times.”