cut up shoulders

believe it or not you CAN toughen the groin region with relentless pounding with a blunt object....just wrap a rock , or brick , in some cloth- and pound it against your balls...the shaolin monks do it all the time....

then challenge a mate to a ball punching contest....let him go first- then watch his face as his fist bounces harmlessly off....then let rip with your own little reply....good luck again man!