What should I do if I get hit in the testicles? (playing soccer): http://www.futboleno.com/tv/juegasano/217
Medically speaking, although getting hit in the nuts is the worst possible pain that a man can feel, it's actually not that big of a deal. It doesn't make you sterile: http://www.m.webmd.com/a-to-z-guides/testicle-injury-faq