An 85 year old man is having a medical prior to marrying a much younger woman, and so the doctor asks him to provide a sperm sample in the jar that he hands him and to come back next week. Next week comes and the jar is empty. "Sorry doc, I did everything I could. I tried with my left hand, and then my right. I got the woman who lives upstairs to try with her hands wrapped over mine, and then on her own. She even put her mouth round it, with and without her teeth in, and still nothing. She even dipped it into warm water for me and tried again" "You got a stranger in to help?" queried the amazed doctor. "Yes" he replied,"But I'm buggered if either of us could get the bloody lid off"