How Taylor Swift and Travis Kelce Pulled Off His Eras Stage Debut in London (Exclusive)

On Sunday, Taylor Swift brought Travis Kelce onstage with her during her show at Wembley Stadium.

After Travis Kelce joined Taylor Swift onstage at the Eras Tour in London on Sunday night, fans immediately began to ask questions about how the surprise appearance came together. Luckily, ET has got the answers.

On Monday, a person close to the couple shared that the Kansas City Chiefs tight end and the "So High School" singer, both 34, have long been planning to get Travis up onstage for a performance and that the stars finally aligned over the weekend at Wembley Stadium.

A source tells ET, "Taylor and Travis have recently discussed Travis making an appearance onstage at the Eras tour, when timing was right, and they finally made it happen. Travis was so excited to support Taylor onstage, and Taylor couldn't be happier to feature him, especially during such a fun, pivotal scene in the show."

Travis' on-stage cameo came during The Tortured Poets Department era as Swift transitions from a dress to a two-piece outfit thanks to her backup dancers. Travis -- wearing a black tuxedo and top hat to match Taylor's other dancers -- carried his girlfriend of roughly a year onstage and stood by as her two other dancers stripped her of her dress while he stood back and smiled. 

Travis Kelce smiles at Taylor Swift as she walks away from him on stage at the Eras Tour stop in London on June 23 - Getty

The source tells ET that while Travis' appearance was manicured to perfection -- including one sweet moment where he pretended to apply makeup to Taylor's face before she began singing "I Can Do It With a Broken Heart" -- he only had a few hours to get it together. 

The source adds, "Travis only had one night of rehearsal, the evening before he performed onstage, and didn't miss a beat. Taylor was beaming from ear to ear as Travis took on the dapper role. The two are hoping he can make a cameo again in the future."

For those who have followed Travis and Taylor's love story, it's no surprise that he was able to pull off the top-notch performance without a hitch as he has devoted countless hours to watching her shows around the world, including Australia, Paris, Kansas City -- where it all started -- and, most recently, three consecutive shows in London. 

One video posted on Sunday evening shows No. 87 -- who Taylor has lovingly referred to as "the guy on the Chiefs" -- standing in the pit at the end of the third and final London show, performing her choreography to "Karma," which is the very last song of the concert. 

After the show had ended, Travis and Taylor were seen adorably holding hands and walking out of Wembley Stadium before jumping in a getaway car and heading off to party it up in the U.K. capital. The duo visited Chiltern Firehouse around midnight and celebrated three sold-out shows with friends, including Ellie GouldingPhoebe Waller-BridgeSophie Turner and her boyfriend, Peregrine Pearson, who also attended the concert

On Monday, Taylor also took to Instagram to reflect on her three-show run and thanked the fans and friends -- some 240,000 in total over the weekend -- who came out to support and rock with her for the show. 

"Wembley Stadium round one was so surreal. Looking out into crowds of 90,000 fans each night and hearing that VOLUME… Those were some of the loudest crowds I’ve ever heard," Taylor wrote. "Acoustic sections went OFF. I got to sing 'Castles Crumbling' with @yelyahwilliams for the first time - hadn't performed with her since 2011 and man my heart was just so full of love for her and our friendship. Then the impossibly gifted and wonderful @gracieabrams came and surprised the crowd with the first performance of our song 'us.'"

She also acknowledged her football star boyfriend's Eras Tour debut, shouting him out individually and tagging him in a photo dump. 

"And I'm still cracking up/swooning over @killatrav's Eras Tour debut 🥰 Never going to forget these shows. Can't wait to do it 5 more times in August. Up next: Dublin!!" she wrote.

Travis Kelce and Taylor Swift hit the town in London after her third Eras Tour show at Wembley Stadium - CH / SPLASH
Travis Kelce and Taylor Swift on stage together on night 3 of the Eras Tour in London - Gareth Cattermole/TAS24/Getty Images for TAS Rights Management

That post came just two days after she and Travis went Instagram official on Friday when she shared a selfie featuring her, Travis, Prince William, Princess George and Princess Charlotte -- who attended the concert on the future king's birthday

"Bday M8! London shows are off to a splendid start 🇬🇧🇺🇸🤝 @princeandprincessofwales," she captioned the photo. 

In May, a source told ET that Travis and Taylor -- who began their love story last year -- have family and friends suspicious of an engagement. 

"Taylor and Travis are doing amazing, and their loved ones see an engagement coming sooner than later," the source said. "They make a great match and there's no question about that."

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