An intersting festival takes place on the second saturday every year in the town of Roca Canterano, a little town outside of Rome (Lazio region). 

It is the "Festa del Cornuto" or the festival of horns (Feast of the Cuckold).  Horns are often used to describe a cheating husband or wife, it is one of the worst insults you can say to a man or woman in Italian.

The festival celebrates anyone who has been cheated on in a relationship or spurned lovers, I guess in a "misery loves company" kind of manner.  People will march through the streets and satirical floats telling stories will pass through the streets.