"Ballsiest" runs deep? Come on, the expression is now acceptable casual language to use when talking to friends - men and women. It's light-hearted, funny, silly, whatever-language. No need to be so serious and reduce everything to the paranoid question "is it sexist and is it harmful to society and the planet".
Our society will be better off if we relax about actual real differences between the sexes, between cultures and races, and have a bit of fun about the differences. As comedians do all the time. It seems like as soon as someone says anything even approaching a casual reference to these natural differences, out comes the sexist/racist red card, followed by a lecture about how we all should know better.