Soccer fans now know why French star Zinedine Zidane head-butted Italy's Marco Materazzi in the World Cup. During an interview in Rome, Materazzi admitted to holding Zidane's jersey, which prompted the Frenchman to tell the Italian, "if you want, I'll give you the jersey later."
In response, Materazzi said he, "preferred his sister."
That was enough for Zidane who responded with his well-known head-butt. He was booted from the game and the Italians won on penalty kicks.