Compared to some of the stories on this thread mine is more disturbing than dodgy, but anyway here’s mine.
Whilst working for Local Government in a large (approx 200 staff) building we had some rather strange posties that would deliver the internal mail.
One particular chap was commonly referred to a the whistling postman. I discovered the reason for this upon walking into the men’s toilets one day, where I discovered him stood at the urinal, both hands behind his head and whistling loudly while having a wazz.
Now luckily I had the option of using the cubicle but he did join me mid flow on more than one occasion when its a lot more difficult to escape.