Johnny Depp has slammed the rumours that he proposed Amber Heard because she was pregnant and said that it wasn't a "shotgun affair".The Charlie And The Chocolate Factory star told NBC's Today show that Heard is a wonderful girl, who is sharp as a tack, wonderful Southern belle, sweet as can be and good for him, the New York Post reported.The couple, who met on the set of the The Rum Diary in 2011, threw a star-studded engagement party earlier this month. Depp has two children with French singer Vanessa Pardis from an earlier relationship.On a visit to China late last month, Depp showed off his diamond engagement ring that he called a "chick's ring". Asked whether he was engaged, the Pirates of the Caribbean star said, "The fact that I'm wearing a chick's ring on my finger is probably a dead giveaway. Not very subtle." He laughed as he lifted up his left hand and displayed a single diamond on a band around his ring finger.