Taylor Swift & Harry Styles Hold Hands After Long Night in N.Y.C.

By Tim Nudd

12/04/2012 at 10:20 AM EST

They're getting closer by the day.

After strolling together in Central Park on Sunday, Taylor Swift and Harry Styles graduated to publicly holding hands early Tuesday after a long night in New York City.

The pop star and her potential boy-band beau were photographed arriving at her hotel after 4 a.m. – she in a thigh-length black coat, he in dark pants and a T-shirt.

POLL: The Romance You Still Can't Believe Happened

Styles, 18, and his band One Direction performed at Madison Square Garden on Monday night, while Swift, 22, attended and performed at the 2012 Ripple of Hope Awards a dozen blocks north at the New York Marriott Marquis.

They met up after at One Direction's afterparty at the Hudson Hotel, where the two performed a Backstreet Boys song during karaoke.

Swift and Styles "joined together up on stage for most of the night," a hotel insider tells PEOPLE. "They played a One Direction song and Taylor sang it."

At the Ripple of Hope Awards, Swift was honored for her commitment to social causes by the Robert F. Kennedy Center for Justice & Human Rights. Several members of the Kennedy family – though reportedly not Swift's ex-boyfriend, Conor Kennedy – were in attendance.

RELATED: Taylor Swift & Harry Styles Visit Central Park Zoo Together (Photo)

• Reporting by CARLOS GREER