In Italy if one has antlers/horns, it means that his girlfriend or wife is betraying him. I found that very disappointing. One of the first things I learnt when I came here; when an idiot mimicked the horn symbol with his hand and my Italian friends explained what it meant. He was a total stranger and drove away immediately, so it didn't mean anything, but I didn't like it. I suppose it's like "wanker" in English, but obviously worse. Plus I had some fun hats with antlers when I was small and I loved them, so you can imagine how I hate that expression.