Now if you're at all familiar with guns, you might have noticed the first clue that this guy maybe isn't the sharpest tool in the shed: He's using a semiautomatic pistol to play Russian roulette -- a game that requires a revolver so that you can spin the cylinder like, you know, a roulette wheel. But he'd emptied the gun of bullets beforehand, so rather than redecorating the wedding cake with douchebrains, when he pulled the trigger it resulted in nothing more than an anticlimactic click. The whole thing was just a harmless little wedding prank, a quaint memory for him and his friends to laugh about in the years to come. Right?
Unfortunately, the virus Dumbassviridae is highly contagious (particularly at parties), and this guy didn't want to be the only one riding the self-inflicted-gunshot-wound train that night. So he recocked the gun and looked around as if to ask who else had the balls to step up to the plate and act like a total jackass, and then a second guy grabbed the gun and repeated the action -- only this time the supposedly empty gun fired a live round into the man's skull.
It's basically Deer Hunter meets Jackass.