See How Jack Antonoff Surprised Taylor Swift For Her Birthday

Taylor Swift took to social media on Wednesday (Dec. 18) to share a glimpse of the surprise birthday celebration thrown for her by frequent collaborator Jack Antonoff.

"Walked into the studio to a surprise birthday party from these two @jackantonoff & Laura Sisk – it's equally wild and cozy to think it was the three of us in a room making a song called Lover here last year," the superstar tweeted alongside a pair of photos from the recording studio featuring a cake and giant balloons spelling out "Happy Birthday."

On Dec. 13, BIllboard's Woman of the Decade rang in her 30th birthday by performing at iHeartRadio's Jingle Ball in New York — where 20,000 fans inside Madison Square Garden sang her "Happy Birthday" — followed by a star-studded Christmas-themed bash attended by the likes of Halsey, Gigi Hadid, Camila Cabello, 5 Seconds of Summer, Queer Eye's Antoni Porowski and Jonathan Van Ness and more. 

Check out pics from Swift's belated birthday surprise below.