"Grandma Ain't No Spring Chicken" joke

There was this couple who had been married for 50 years. They
were sitting at the breakfast table one morning when the old
gentleman said to his wife, "Just think, honey, we've been married
for 50 years."
"Yeah," she replied, "Just think, fifty years ago we were sitting
here at this breakfast table together."
"I know," the old man said, "We were probably sitting here naked
as jaybirds fifty years ago."
"Well," Granny snickered, "What do you say... should we get naked?"
Where upon the two stripped to the buff and sat down at the table.
"You know, honey," the little old lady breathlessly replied, "My
nipples are as hot for you today as they were fifty years ago."
"I wouldn't be surprised," replied Gramps. "One's in your coffee
and the other is in your oatmeal!!!"