I once read about a Wisconsin couple playing sex games with guns. Last time, the shot gun (!) was loaded and blew off the guy's testicles. Imagine - being hot & horny, about to cum and then - whoom!
http://archer2000.tripod.com/lawdisorder/lawback22.html

And, of course, that granny that shot her granddaughter's rapists' balls (and one dick) off.
http://www.freerepublic.com/forum/a38a827196b4b.htm

Does anyone have some scenes from the movies mentioned?