As every football fan around the World knows, it's customary to scream at the referee, using obscenities to describe his eyesight or even to question his parentage.
But what if he, is a she? When does boys' banter become sexist abuse?
Matt O'Donoghue asked some male football players their views on female refs. Jenni talks to female referee Janie Frampton and is also joined by Simon Easson, head of Sport, Media and Culture at De Montfort University.