Taylor Swift and Harry Styles holding hands arrive at Taylor Swift's hotel at 4:11am in New York City on December 4, 2012. Credit: Alequin/Bosch/INFphoto.com

Taylor Swift had a busy night in the Big Apple Dec. 3.

After being honored with the Ripple of Hope Award -- by her ex-boyfriend Conor Kennedy's family! -- on behalf of the RFK Center for Justice and Human Rights, the 22-year-old met up with her latest boy toy, One Direction's Harry Styles.

The boy band singer, 18, had just finished performing with his bandmates Niall Horan, Zayn Malik, Liam Payne and Louis Tomlinson at New York City's famed Madison Square Garden. "It was the best night of our lives!" Horan, 19, tweeted. "Thank you, thank you, thank you!"

The new couple joined the other One Direction members for karaoke at the Hudson Hotel, according to one Twitter user who snapped a picture of Swift, Styles and Horan performing the Backstreet Boys' 1998 hit "I Want It That Way." Just before 4:15 a.m., Swift and Styles were photographed holding hands outside the "Red" singer's hotel.

The young musicians -- who were spotted flirting backstage at The X Factor in mid-November -- were first photographed together in Manhattan's Central Park Dec. 2. They were joined by Styles' stylist, Lou Teasdale, her fiance, Tom Atkin, and their 1-year-old daughter, Lux.