One of my worst approach and landings was in my early days doing a charter flight on a light twin. It was single crew and I was desperate for a pee. I had considered diverting en route. A goaround was not an option I wished to exercise. Consequently my judgement was very biased due to the uncomfortable circumstances. A friend had a similar problem when a bout of food poisoning caught up with him in a Navajo Chieftain on a mail run. Do any modern exec jets have a "P" tube in the flight deck for relief like the Kingairs used to have?