Getty Images

Perhaps the greatest feud of 2015 was between Justin Bieber in a Nirvana t-shirt and every rock music purist in existence. Basically, people were not happy when the dude rolled onto many a red carpet supporting the late great band, even though his stylist swore by his love of the band and Kurt Cobain's widow / punk goddess Courtney Love totally approved.

Biebs has also been rocking Metallica shirts, much to the chagrin of metalheads everywhere. Jokes on them: The band loves it.

As the NME points out, frontman James Hetfield posted a list of his 'Top 10 Thingz Of 2015' for the band's fanclub. Coming in at number 10 is "Justin Bieber wearing a Metallica shirt." You can see it here, nonbeliever.

Cool, right? Worlds colliding and such. Take our How Metal Are You? quiz and see how you stack up. Make sure to click through our hilarious gallery of metal's best dressed, too. Maybe one day we'll see JB in there.