Those urinals that have no dividers between them are the worst. Old Oak bar a prime example. When someone is at the next urinal i usually cant piss. A mind block thing. Then i look all gay. Its worse when you have someone on both sides.When I was first going to pubs that was simply known as "the rule".
Similarly I have no problem showing my cock, or letting another man suck it. But at least let me piss first.
Unless he requests that I do that while he's sucking. In which case I will wait.