In a video posted on Twitter, the president called him the 'worst mayor in the history of New York' and Trump Jr tried to follow suit by sharing footage of apparently a New York street where the sidewalk was littered with rubbish.
Trump Jr told him that 'rather than pulling a PR stunt,' de Blasio should concentrate on 'cleaning up his own backyard first.'
Rather than do a PR stunt “run” for President (we all know it’s going nowhere) maybe @NYCMayor should clean up his… https://t.co/cS9ra5GCpz
Trump Jr didn't specify where the video had come from or why there was so much rubbish on that particular street but it soon emerged that it wasn't rubbish at all but sleeping bags and blankets that belonged to fans of the world famous K-pop group BTS who had been camping out ahead of the band's concert in Central Park.
Trump's notifications were soon inundated with people telling him the truth and inadvertently embarrassing the 41-year-old's shallow dig at de Blasio.
@DonaldJTrumpJr @NYCMayor Someone tell Eddie Munster that it’s not homeless; it’s kids camping out all week to see BTS.