Picture your average Tuesday night: does it involve the future king of England letting rip to Livin' On a Prayer alongside the man who penned the track, Jon Bon Jovi, and the princess of pop, Taylor Swift? Erm, NO! Well, this perfect-storm of a sing along came about yesterday at the Winter Whites Gala, thrown by Prince William at his and Kate's Kensington Palace pad (although Kate wasn't in attendance – she was busy looking after George) in aid of Centrepoint, the homeless charity he is a patron of. Appaz Jon Bon insisted William join him for an acoustic version of the karaoke fave after hearing Wills had sung the song at his cousin Zara Phillips' wedding (again: amazing). William got backup from Taylor, who was a total karaoke-keano, screaming, swaying and double-high-fiving Wills the whole way through. This is how you karaoke, people – watch and learn.