Piers Morgan has hit out at Prince Harry once more, branding him a "whiny little brat" after the trailer for the Duke's new mental health series came out.The 56 year old, who recently taunted his Good Morning Britain replacement Alastair Campbell after he mistakenly announced the Queen's death, took to his Twitter feed to re-share the trailer for The Me You Can't See for his 7.9million followers to see before going on a rant.The Apple TV+ series, which airs on 21 May, sees the 36 year old Duke of Sussex and talk show host Oprah Winfrey speak out on the importance of seeking help around mental health as they hear from celebrities like Lady Gaga and Justin Bieber.