US President Donald Trump's son Eric answered if his half-brother Barron really told ex-President Joe Biden to "go f**k" himself at their father's inauguration, which lip-reading experts had claimed. "I asked Barron, 'Buddy, what did you actually say?' It was something so polite I…wouldn't get it right," said Eric, adding Barron told Biden, "Congratulations and best of luck to you."