Long before his marriage to Meghan Markle and royal exit, Prince Harry had a reputation as the prankster of the royal family. In his new book, Long Live the Queen! 13 Rules for Living from Britain's Longest Reigning Monarch, royal author Bryan Kozlowski reveals Harry once pranked his grandmother, Queen Elizabeth, by recording a hilarious new outgoing voicemail message on her personal cellphone. According to Kozlowski, the Queen turned to her grandkids for help learning to text (as grandparents do) and Harry would then sneak off with her personal cellphone and record a new (and hilarious) outgoing voicemail message. In the book, Kozlowski writes:"Prankster Prince Harry reportedly used the opportunity to record the following voice mail message on his grandmother's cell: 'Hey, wassup?