This isn't a urinal story, but it applies.
In the days after 9/11, airports added extra security at the gate. They would ask for certain carry-ons to be put on a table for inspection and they would pull some people into a small area surrounded by curtains held by metal pipes for a pat down or wanding. A black guy was in line in front of me and called into the screening area. They wanded him and he set the buzzer off. I got sent to the table area for my carry-on to be checked and ended up beside a lady. The table was on one side of the screened area. We heard the black guy say, "That's just my piercing." The lady looked up where the curtains came to the metal pipe and left a hole where she could see through. She said, "That's bigger than the pipe!" I looked up to see what she was talking about. The black guys cock was on display through the curtain gap and it was as thick as the pole and hanging down to an unbelievable extent, ending with a huge ring in his PA.