While out one morning in the park, a jogger found a brand
new tennis ball, and seeing nobody around it might belong
to, he slipped it into the pocket of his shorts.

Later, on his way home, he stopped at a pedestrian
crossing, waiting for the lights to change.

A girl standing next to him eyed the large bulge in his
shorts. “What's that?” she asked.

“Tennis ball,” came the breathless reply.

“Oh,” said the girl sympathetically, “that must be painful,
I had tennis elbow once.”