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Kansas City Chiefs star tight end Travis Kelce has enjoyed a 10-year career in the NFL, but Sunday marked another first for him. He made his on-stage debut with pop star and girlfriend Taylor Swift during the latter's show in London's Wembley Stadium as part of her world-renowned Eras Tour.

The 6'5" Kelce, clad in a top hat and tails, popped up on stage during Swift's performance in the hit song, "I Can Do It With a Broken Heart" off her most recent album, "The Tortured Poets Department." The song's introduction features two dancers forcing Swift into a costume change before she launches into the performance. Kelce, however, was the surprise third dancer who aided in the effort, carrying her to a red couch and then helping Swift touch up her makeup as she was stripped out of a jacket, revealing her sparkly white two-piece.

While Swift and Kelce have not been shy about their relationship, which sparked up some time last summer after he publicly called her out on his podcast, "New Heights," this is his first time taking the stage with his billionaire girlfriend. He has, however, been seen in the VIP tent frequently during breaks from football, while Swift was a constant presence at Chiefs games during the season. On Saturday, the couple went Instagram official when Swift posted a selfie of them, Prince William and two of the royal children, Prince George and Princess Charlotte, taken backstage at her show. 

Sunday's performance marked the third one of the Eras Tour in London before moving on to Dublin, and Kelce has been present for all three. His brother, former Eagles center Jason Kelce, and sister-in-law Kylie were in attendance for the first two dates. Other celebrities there this weekend included Mila Kunis, Ashton Kutcher, Liam Hemsworth, Greta Gerwig, Jon Bon Jovi, Paul McCartney, Nicola Coughlan, Cate Blanchett, Phoebe Waller-Bridge and Andrew Scott.