from the international ctr for bathroom etiquette
First, a note on talking
Usually, talking at a urinal situation is frowned upon. Conversation may occur directly prior to urinal use, or directly after it, but while engaged at the urinal, verbal communication should be nil. Furthermore, actual conversation may only occur between two individuals who entered the washroom together. Under no circumstances should you start a conversation with someone whom you simply discovered to be in the bathroom when you arrive. A simple grunt or monosyllabic word is acceptable to acknowledge the other's existence, but that is all. Period.