LONDON — Taylor Swift may have once loved a London boy, but on tour in the British capital, it’s her American beau taking center stage with her.

       On Sunday night, Travis Kelce made a surprise onstage appearance during Swift’s Eras Tour set before tens of thousands of fans at Wembley Stadium — the same weekend as Swift’s Instagram selfie with the British royals and the Kansas City Chiefs tight end, who was wearing a USA Olympics hat.