From Wikipedia, an old joke about Calvin Coolidge when he was President … The President and Mrs. Coolidge were being shown (separately) around an experimental government farm. When [Mrs. Coolidge] came to the chicken yard she noticed that a rooster was mating very frequently. She asked the attendant how often that happened and was told, "Dozens of times each day." Mrs. Coolidge said, "Tell that to the President when he comes by." Upon being told, the President asked, "Same hen every time?" The reply was, "Oh, no, Mr. President, a different hen every time." President: "Tell that to Mrs. Coolidge."
—?The joke appears in a 1978 book (A New Look at Love, by Elaine Hatfield and G. William Walster, p. 75), citing an earlier source