We knew Maroon 5 were big but we didn't realise they were screaming-mob-in-a-subway-station big.

Jimmy Fallon's newest bit on 'The Tonight Show' involves sneaking musical guests into a New York City subway station in disguise and this time it was Maroon 5's turn to don their wigs and fake moustaches and give a surprise performance of 'Crazy Little Thing Called Love' and 'Sugar' to some unsuspecting New Yorkers.

At least they were unsuspecting until Fallon told them exactly what was happening and then all hell broke loose.

We honestly don't get why Adam Levine is such a thing but we're willing to chalk it up to another one of the baffling truths of 2017.