Giving my arse an headache

Just watching the semi final of the Junior Apprentice and during Lord Sugar's summing up, for some reason an old expression my dad used to use came to mind "you're giving my arse an headache". I actually thought my dad had made it up until I heard it used in an episode of Only Fools and Horses. If you hadn't worked it out it is used when someone has a touch of verbal diarrhoea.