Taylor Swift performs 'King of My Heart' for newly engaged couple

Feb. 25 (UPI) -- Taylor Swift helped fan Alex Goldschmidt celebrate his engagement to boyfriend Ross Girard with a special performance in Los Angeles.

Swift made a surprise appearance during Goldschmidt and Girard's engagement party on Sunday to perform an acoustic version of "King of My Heart."

Goldschmidt told CNN he reached out to Swift and her publicist to thank her for writing "King of My Heart," the song he was listening to when he decided to propose to Girard.

"She reached out wanting to be a part of it," Goldschmidt said. "It was all her idea."

Goldschmidt posted on Instagram video of Swift's appearance at the engagement party and ensuing performance.

"This is from Alex, but sung by me," Swift says in the video. The pop star's appearance shocked party-goers and Girard.

Swift and her actor boyfriend, Joe Alwyn, did not walk the Oscars red carpet on Sunday and instead attended Vanity Fair's annual Oscars afterparty. Alwyn stars in The Favourite which was nominated for 10 awards and won Best Actress for Olivia Colman.

The couple were spotted by fans showing affection for each other during the party. Swift donned a gold fringe mini-dress that she displayed on Instagram.