Piers Morgan surprised his fans as he posted a tribute to his wife Celia Walden in honour of her 45th birthday on Tuesday.Sharing a rather sexy throwback picture of his wife, the Good Morning Britain host wrote: "Happy Birthday to my wife Celia… aka The World’s Luckiest Woman." He then joked: "I only married her for her tatts."MORE: Piers Morgan shares photo of daughter Elise following in his footstepsWATCH: Piers Morgan celebrates daughter's birthday live on GMBKatherine Jenkins was one of the