Justin Bieber has been working on an image overhaul for the last year or so, but his sense of style still leaves a LOT to be desired.

The 21-year-old is generally seen in oversized tank tops, jeans and massive baseball caps – and even on the red carpet he tends to get it a bit off the mark.

Case in point has to be last night's Grammys, when the Where Are U Now singer showed up in a pretty dull monochrome outfit.. a far cry from his ex Selena Gomez's breathtaking appearance in a sequined sapphire blue number.

Justin's shirt-and-suit-pants outfit, combined with the faint hint of a blond mustache, earned him a fair bit of stick online – in particular from Irish comedians The Rubberbandits.

"Justin Bieber went to the Grammys looking like a leaving cert student who just got a job collecting glasses in a Monaghan nightclub," the lads wrote in a Facebook post which has already racked up a whopping 31,000 likes since it was posted early this morning.

"That's a massive insult to leaving cert students in Monaghan," one sly-tongued commenter wrote, with another adding, "It beats going to the Grammys looking like Justin Bieber."

Thankfully Biebs had an outfit change before he headed on stage to perform Love Yourself and Where Are U Now in front of a jampacked audience of celebrities.

However we can't help but noticing that he's still in desperate need of a shave…