Itchy, crusty and stinky residue left over on the underside of the scrotem, usually do to an improper back-to-front wipe motion (for those who actually use toilet paper). It demonstrates extremely poor hygiene and is found to cross all racial and ethnic origins.
I was about to get a blowjob until she found out I had poopy nuts. Now I will never get any play because she told all her friends. Maybe I should try switching it up. I heard that gay men love poopy nuts.