It's a localized slang usage. A Spanish-born speaker wouldn't get it, but a Puerto Rican would. I had it happen in a school I worked in. The Spanish teacher was from Spain and didn't understand the big deal when the Puerto Rican kids called people they that. I remembered that from knowing a few Puerto Rican sergeants when in the army. Wevos head was the nickname for one guy.
And ass in Britain still just means a donkey.
"The only thing a man should take seriously is the fact that nothing is to be taken seriously."
Samuel Butler