Dude, I'm 26 and would have no problem beating the ever livin' shit out of a 12 year old holding a knife to any part of me. Age ain't a problem. The parents apparently have their own problems that they're passing down to the kids. This kid either needs discipline or drugs. My advice would be either to stay away from that place or talk to your friend's parents about putting the kid on some meds or disciplinary program or something. Lack of discipline may be the problem, but it sounds to me like he needs meds.