It's taken him two years, but Jimmy Fallon has expressed regret for that infamous 'hair tousle' interview he conducted on his show with Donald Trump in 2016.

At the time, Fallon was roundly criticised for pandering to Trump (before he was elected) instead of asking him tougher questions or challenging him in any way - with one critic suggesting that he had lost the 'last shred' of “any credibility as a thinking comedian with a point-of-view”.

In recent days, Fallon has spoken about his regret regarding the show - which of course, mortally offended Trump, who took to Twitter to denounce the "whimpering" talk show host, and demand that he "be a man":

 Fallon's response, meanwhile, was simple but effective: