I have been in any number of conversations & situations over the years involving scrotum play. I have had partners who blast if I gave the slightest attention there, and others who were less sensitive but clearly enjoyed it. Alas, when a guy touches, licks, sucks or otherwise attends to my balls, it does virtually nothing--as with my nipples, I seem to have little sensitivity there. *Sigh* I am the original numbnuts.