So the envelope thing, the OP did say he read prossienet so that's where that was probably picked up from.
As I am feeling benevolent today so I suppose the scenario could have been like this..... The girl states on her profile that she is on holiday from the 10th to the 18th June so could have been "de-mob" happy. She may have been out shopping with a prossie mate for her hols ( maybe they off together). She is running late from shopping (45mins) and doesn't want to risk losing some more holiday money but knows she is going to be off to a bad start with a new client ( that's assuming the girl has a conscience!). Her mate is in a good mood having spent the morning shopping so suggests that she joins them for a laugh, so she does and it saves her waiting in the car for an hour or hiding quietly in the flat somewhere..
The OP, on his first punt ever, can't believe his luck and naturally is anxious to tell the world about it, as anyone of us would if it happened to us. Because he is new, he is not believed and there we have it.
So I am going to keep an open mind on it until it is proven one way or t'other. Just because it hasn't happened to me doesn't mean it can't happen to someone else. There are things that I experience that others wouldn't believe so I shall wait and see. It would seem a strange time to tout her when she is away for a week in a few days - unless she needs some quick holiday cash? It's not like the bogof is a regular thing anyway, just lucky circumstances?