Taylor Swift and Harry Styles sang a karaoke duet to celebrate One Direction's biggest gig this week.
The couple teamed up to sing a rendition of Kenny Rogers and Dolly Parton's classic Islands in the Stream at the Hudson Hotel after the 18-year-old and his bandmates had performed to 20,000 screaming fans at Madison Square Garden in New York.
A source told The Sun newspaper : "It was brilliant. There was a huge cheer when they got up."
Following the performance, Styles wrote on Twitter: "Last night was the best thing I have ever done.
"We're on an Island over the Stream... (sic)"
Band joins in
Swift, 22, and Ed Sheeran, 21, then joined Styles and his fellow One Direction bandmates - Niall Horan, Zayn Malik, Louis Tomlinson and Liam Payne - to sing the Backstreet Boys' 1998 hit I Want It That Way,.
Swift and One Direction also teamed up to sing Vanilla Ice's Ice Ice Baby.
Swift and Styles - who went for a romantic stroll around New York's Central Park prior to the gig - also performed Sir Elton John and Kiki Dee's classic hit Don't Go Breaking My Heart before heading back to their hotel in the early hours.
One partygoer told the Daily Mirror newspaper : "It was the perfect song for a new couple - they were both giggling as they sang it to one another.
"It was very fun and very relaxed. Everybody was in really high spirits. You could tell they are very comfortable in each other's company.
"They were still smiling when they disappeared back to her hotel hand-in-hand in the early hours of the morning."
Zayn Malik was accompanied at the gig by his girlfriend, Little Mix singer Perrie Edwards, and her brother Jonnie also teamed up with One Direction - whose rider featured a host of calorific treats including Snickers, KitKats and cupcakes - to sing at the afterparty.