Two teens had been lovers for a few weeks, but the boy was always after the girl to quit smoking. One afternoon, she lit up after some lovemaking, and he said, "You really ought to quit."
She, getting tired of his nagging, said, "I really enjoy a good cigarette after sex."
He replied, "But they stunt your growth."
She asked if he ever smoked, and he replied that he had never. Smiling and lifting her gaze to his groin, she said, "So, what's your excuse then?"