A man was walking in the park when he spots a tennis ball lying on the ground. He picks it up and inspects it. There are no tennis players about so he thinks "I'l take this ball home for Fido to play with" and sticks it in his pocket.
An old lady wanders up to him and points to his bulging trouser pocket and asks "whats that sonny?" "tennis ball" the man replies, the old lady screwed up her face, "oh, that must be sore sonny, i had tennis elbow once"
