Eight years later and Prince William is still cringing about his viral karaoke moment with Taylor Swift.

On Monday (Dec. 6), Apple Fitness+ released the latest episode of their “Time to Walk” series featuring the Duke of Cambridge. William spoke about the 2013 palace charity event where both Swift and Bon Jovi were set to perform. Somehow, William ended up on stage performing a song that he didn't even know the words to.

“Little did I think what was going to happen next. I’m sat next to Taylor Swift. She’s on my left. And after Jon does his first song, there’s a pause, and she turns to me,” he recalled. “She puts her hand on my arm, looks me in the eye and says, ‘Come on, William. Let’s go and sing.’”

He admitted, “To this day, I still do not know what came over me.”

The trio ended up singing "Livin' on a Prayer" together, only William didn't know the lyrics.

“Honestly, even now I’m cringing at what happened next, and I don’t understand why I gave in,” he continued. “If Taylor Swift looks you in the eye, touches your arm and says, ’Come with me,′ you basically do what she says.”

William said that he "got up like a puppy" and believed at the moment that it was a "great idea" to follow her. He shared that he was in a trance for the first part of the song when he suddenly realized what was happening.

“I’m thinking to myself, ‘Am I standing on the stage singing 'Livin’ on a Prayer' when I don’t even know the words?’ I thought, ‘Well, if they’re enjoying it, then the night is for them. So sod it. I can’t be the doofus who’s going to ruin it for everyone.’”

William also admitted that in the moment, he attempted to keep his cool but was sweating and panicking internally.

“A lot of people might think that I’m comfortable on stage," he added. "When I do speeches and things like that, I’ve done so many now, they’re not a problem. But I’ve not done singing.”

Meanwhile, Swift had a different story about how the karaoke singalong came about. The "All Too Well" singer told Graham Norton back in 2014 that it was Bon Jovi who invited the prince on stage and that he begged Swift to come with him since he didn't know the lyrics.

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