Just along similar lines as Funboy3's thread about being hassled on the way to an appointment by hotel staff it made me think of another highly amusing situation:
In which you are on the way OUT and you meet another punter on the way IN!!!! The furious downward glance to avoid eye contact, the hunched shoulders and the brisk march forward, body turned to avoid physical contact...the patina of shock, embarassment and lead-in-the-belly panic (did we recognise each other???) is palpable almost as a smell!!!!
I know, I know, it hardly ever happens in this day and age but back when there was actual brothels it was a very frequent occurence.
Personally I always went out of me way to say hello and be sociable