A young man, having secured as his companion for an evening a girl of no good repute, and living in a very small town, perhaps near the sea coast, and having a decent amount of fear for the health of his generative organs, found himself in a pharmacy purchasing prophylactics.
He approaches the counter, and speaks with the proprietor, entreating that man to sell him a french letter of fine vulcanized rubber, stout enough to withstand the onslaught of ill humors certain to flow freely from the congested female area of that ill-favored, yet generous lass, once she found a state of excitement; yet, the young man continued, of a thinness and delicacy that he should be able to enjoy the skills the young lady had learned from her many companions who had been to the orient.
The gentleman behind the counter, a chemist by trade, saw from the glint in the young man's eye that he had buggery on his mind. The two men laughed together, and talked of the many variations of vulvae they'd encountered, and shivered together with fright at the pox!
They young man purchased his contraceptives, and went on home to prepare for his encounter with the harlot. He set out, as was the custom, to pick up the young girl of expansive temperament from her parent's home. Yet he was soon chased down the walk by a man he recognized as the pharmacist!
The young man cried out..."But your fly is open, your cock is hanging out, and there is come dripping on your shoes!"