When I was a shy 20 year old, I was on a long distance coach which in those days had no on-board toilets as they do nowadays, I was too embarrassed to ask the driver to stop for me to take a wee, so I held on as long as I could, but eventually got the shakes and started to feel ill, so I just let it out slowly into the upholstered seat below me with another passenger sitting right next to me who had no idea what I was doing.