LBJ was not only the president, he was also a prodigious urinator, who pleased himself by pissing on his Secret Service detail while shielded from public view, according to Mental Floss's Jenny Drapkin:

Johnson lived to dominate, and he used crass behavior to bend people to his will. At 6-ft., 3-in. tall and 210 lbs., he liked to lean over people, spitting, swearing, belching, or laughing in their faces. Once, he even relieved himself on a Secret Serviceman who was shielding him from public view. When the man looked horrified, Johnson simply said, “That’s all right, son. It’s my prerogative.”

LBJ: The President Who Marked His Territory (via Reddit)

(Image: LBJ, a Creative Commons Attribution (2.0) image from pagedooley's photostream)