Some "Tonight Show" viewers weren't laughing after GOP presidential hopeful Donald Trump paid Jimmy Fallon a visit Thursday, and encountered nothing hairier from the NBC host than a head rub.
Noting that "the next time I see you, you could be the President of the United States," Fallon proposed they do something "that's just not presidential, really, something that we could do now that we're both just civilians."
"I'm not liking the sound of this," Trump said.
"Can I mess your hair up?" Fallon asked, quickly adding, "I'll be gentle."
Fallon was, both with mussing up Trump's legendary yellow 'do and...