The 25-year-old entertainer and Nick sang his hit “Jealous” together – but he wasn’t the only special guest that evening.
Also pictured inside: Gigi and her boyfriend Joe Jonas, as well as Nick leaving for the concert earlier in the evening.
Watch the performance of “Jealous” below…
FYI: Gigi is wearing Black Orchid cargo trousers and Finlay & Co. sunglasses. Nick is wearing black J Brand jeans.
15+ pictures inside of Taylor Swift, Nick Jonas, and more on stage in New Jersey… More Here! »