"Cabrón (literally 'large goat'), in Spain, Mexico and Puerto Rico, implies a prick or a motherfucker. It may also imply that one's significant other is unfaithful and even worse they are aware of the fact and they're either too weak or stupid to do anything about it; a cuckold. Among close friends, the term is often inoffensive; however, it is not a word to be used casually with strangers."
Image: Autoritratto Cornudo by Salvatore Romano
"Cuckolds have sometimes been written as 'wearing the horns of a cuckold' or just 'wearing the horns'. This refers to a tradition claiming that in villages of unknown European location, the community would gather to collectively humiliate a man whose wife gives birth to a child recognizably not his own. According to this legend, a parade was held in which the hapless husband is forced to wear antlers on his head as a symbol of his wife’s infidelity. Whether this did actually happen or not is irrelevant to the phrase, which survived."
"In Italy, if the 'horns', i.e., the stretched fingers, are surreptitiously placed behind someone's head, or explicitly pointed at a person, the conveyed meaning is that that person is being cheated on by his wife or (more rarely) her husband. Hence the Italian cornuto, that translates literally to having horns, but figuratively means cuckold."
Sources: wikipedia.org: "Spanish profanity", "cuckold", "corna"
