An elderly couple, still very loving after all these years, is shocked when the woman's doctor says she has a heart condition that could kill her at any time. She is to avoid stress, eat right, and never, ever have sex again--the strain would be too much. The couple reluctantly tries to live by these rules.
Both get really horny over time, however, and the husband decides he'd better sleep downstairs on the couch to guard against temptation.
This works for a few weeks, until late one night when they meet each other on the stairs--she's coming downstairs, he's heading up. "Honey, I have a confession to make," the woman says, her voice quavering. "I was about to commit suicide."
"I'm glad to hear it, sweetie," the man says, "Because I was just coming upstairs to kill you!"