Taylor Swift Kisses Partygoer on Stage During Performance With Nelly

08/07/2016 04:28 pm EDT

Taylor Swift let loose Saturday night and her beau Tom Hiddleston wasn't even there!

People at a birthday celebration for Karlie Kloss and the oil her Mike Hess in the Hamptons over the weekend got to witness a duet performance with Taylor Swift and Nelly. The pair performed Nelly's 2002 classic, "Dilemma" on stage and it was documented by many on social media.

Things got interesting when Hess, a Harvard Business School graduate and oil heir, joined Swift onstage. It was confirmed to E! News that he was the birthday boy that evening.

In a video shared jewelry designer Jen Meyer, the two were innocently flirting and dancing when Swift laid a kiss on his cheek.

An insider told E! News, ""Taylor was in an amazing mood, and super fun all night. She danced her ass off. At first she didn't want to perform but then Nelly asked her. Everyone was super into it, the crowd loved it."

Hess and Swift did not hang out for too long during the night because she was with her BFF Karlie Kloss who celebrated her 24th birthday earlier this week.

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