Taylor Swift was reportedly spotted kissing oil heir Mike Hess while performing at his birthday party in the Hamptons on Saturday (6 August). Interestingly, the incident happened when her boyfriend Tom Hiddelston was not present. Apparently, the songstress was at the party to perform the 2003 hit song Dilemma with Nelly.

The video from the party, which has been doing the rounds on social media, shows the Blank Space hit-maker take the stage to perform the duet with the rapper. The original duet with Nelly was performed by Kelly Rowland.

During the 26-year-old singer's performance, Hess - who is a Harvard Business School graduate - joins the singers on stage. Next, Swift's and the birthday boy can be seen flirting with each other as they dance together with Hess's arms wrapped around her waist.

A source told E! News although the singer's boyfriend Tom Hiddleston was not present at the party "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".

Hiddleston is currently filming Thor: Ragnarok in Australia. The 35-year-old actor can breathe easy as his girlfriend spent most of her night with close pal Karlie Kloss, who earlier this week celebrated her 24th birthday.

Swift and the British actor started dating earlier in June, just days after the singer split from Scottish DJ Calvin Harris, who she dated for 15 months.

The party was attended by the likes of Heidi Klum. Hamilton star Leslie Odom Jr also performed in the party.

Taylor Swift
Taylor Swift and Tom Hiddleston started dating earlier in June Danny Moloshok/Reuters