updated 12/04/2012 AT 10:00 AM ET
•originally published 12/04/2012 AT 10:20 AM ET
They’re getting closer by the day.
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.
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.
Reporting by CARLOS GREER