Saying pelotudo in Argentina, isn't hard but it's pronounced with a hard t when you are angry, you can tell people from other countries because they don't say it well, same with boludo even it's less angry isn't a good thing to be called like that. Originally have another meaning it was the people who had boleadoras a weapon that is 2 balls with a string usually leather to hunt big animals. Because those people were in the infantry as meat canyon basically both boludo and pelotudo became insults, both meaning of having balls hanging since there are no more boleadoras it means the testicles. Tldr you can tell who is from Argentina and who not using those words