Credit: Complex

Bloody Bieber!

Justin Bieber seriously toughens up for the April issue of Complex magazine.

In a shockingly graphic new cover shoot from photographer Tony Kelly, the slightly less squeaky clean pop star, 18, referees a boxing match -- but things go wrong pretty quickly.

Wearing a white shirt, black bowtie and black pants, the "Baby" singer gets roughed up by two beefy shirtless boxers. Selena Gomez's boyfriend gets punched and bloodied in the imagined melee.

He also opens up to the magazine about his high-profile relationship with Gomez, 19 -- and how it can be hard dodging paparazzi as they go about their romance.

"There's no way to hide the relationship completely, because then it would be unfair to us," he tells Complex. "It's like, 'You take this car, and I'll take this car, and then we'll meet up at the spot. Then, you go in this door, I'll go in this door. We'll end up crossing ways. You get back in this car.' At that point, it's not even a relationship. Youre just hiding from everyone. That's unfair and unhealthy, man."