Mumford & Sons have revealed that Sir Elton John warned them not to take their genitalia out whilst backstage at the Grammys.

The amusing and somewhat surreal incident came before the 'Babel' boys were due to perform live at the star-studded event earlier this month.

Revealing the anecdote to Zane Lowe at the BRITs, banjo player Winston Marshall said that Sir Elton John told him to not to get his "c*ck" out after asking how the 'Rocket Man' star was doing. He said:

"We were getting ready and were a bit nervous, a bit sweaty. Sir Elton goes, 'Winston, Winston! Come over here'. So I [went] over - I think legally we're obliged to as it's Sir Elton - and I said, 'You alright Sir Elton, what's up?'. He goes, 'Winston, now would be a f**king terrible time to get your c**k out'."

He added: "Elton John is an absolute lad. He's a hero. He made that whole thing fun, because it was so weird."

Mumford & Sons meanwhile otherwise enjoyed a successful 2013 Grammys, winning the Best Album and Best Long Form Music Video awards.