Dominoes
This young lad played dominoes with his workmates every lunchtime, and every lunchtime he'd win. He walloped 'em; he beat them hollow.
Well, one day, the lads had had enough. After their dommies session, they grabbed the young'un, they ripped his kecks off, and they shoved the dominoes one by one, up the cheeks of his bottom.
The poor young'un was ill after this treatment, but he just about managed to stagger down to the surgery. He stumbled into the waiting room, and barged straight through the door to see the doctor.
The doctor looked up, and said "Hey! Don't you ever knock?"