and guys have somehow been conditioned to believe that is does hurt. but actually they just hold them and roll around and it's not hurting. guys do it even if they don't get hit directly in the balls. look at this harry styles gif for example

http://weknowgifs.com/wp-content/uploads/2013/02/harry-styles-hit-in-balls.gif

it doesn't even seem to score a direct hit and his brain (due to programming) reacts as if the world's worst pain is going on.

in conclusion, stop pretending your balls hurt