Pretend that you're the kid's father and constantly apologize to the other players for his behavior.
"I didn't raise him this way - his mother dresses him like a girl and it's warped his mind."
"I knew I'd regret giving him an Xbox for Christmas, but he swore he'd only play Kinectimals and Lollpop Chainsaw."
I might have to try this.
"Sorry guys. His therapist thinks if he can release some aggression in a safe environment before bedtime it might help with his chronic bedwetting."