It happened: Justin Bieber punched a fan in the face

He was left with a bloody lip.

By Bianca Mastroianni

J.B and his fans haven't had the smoothest of relationships.

He's told them they suck, spat on them, had many on stage tantrums and even chose a ~fling~ with Sofia Richie over their devotion... but, punching a fan in the face might top the list.

BUT, before you go boycotting Bieber from your life and trending #JustinBieberIsOverParty... he had a pretty valid reason.

Last night when Justin was driving by a group of fans before his concert in Barcelona, one fan ran up to his car and stuck his hand inside.

TMZ captured the vid, where you can see Bieber responded (in self-defence) by jabbing him in the face, who was left with a bloody lip.

The fan nor Bieber has yet responded to the incident but BLIMEY this is kind of intense.