I remember being approached by such a lady at 8am one morning, outside UMIST. Not that I was interested anyway, you understand, but the trouble is, at that time, you don't know if they're clocking on or clocking off. I didn't want to be rude so did have a conversation about how I wouldn't be taking her up on her offer, but it was always in the back of my mind that some pimp might step out at any moment and claim that my 30 seconds of conversation was tantamount to entering into a contract....
...for shagging (those last two words were superfluous, but I thought I'd use my new found power).