Jesus, is this some kind of European thing? I run with a prettly liberal, hard-drinking social circle, and I think all the women would be fairly well disgusted if some guy pulled his dick out so they could all marvel at the size. And these are sexually empowered and very open women.
And, no offense, but the addition of the women standing around fondling your erect penis from the original story makes it sound an awful lot like a fantasy - I'm not trying to start shit, but I just read an article about the psychology of sexual fantasies on internet message boards, and one of the tell-tale signs of fantasy posting was an increase in the detail, level, and scope of a given situation once other posters have acknowledged and legitmized the fantisizer's post. Generally they can never resist embellishing the original fantasy scenario once a few people have gratified them by verifying the fantasy.
Interestingly, I also once read another article about fantasy scenarios in general, and it flatly stated that one of the most common male fantasy ideals is the exposure and impression of his penis to female friends and co-workers, who then express admiration and amazement at his size and vigorous nature. The male is almost always a 'passive participant' in these scenarios, meaning that the women instigate the behavior and lead the action, absolving the man of any resonsiblity for the situation. This aspect of the fantasy is thought to be a result of the man's actual desire for some sort of sexual contact with the women in the fantasy and a expression of positive self-image - which is generally a good thing.
I'm sorry if it comes across as boorish, but the scenario of your wife pulling out your massive penis (8.5" X 6.5" is bigger than virtually any adult entertainment star and larger than almost anybody that has posted pics on this site, so it is very convenient that you simply just don't post pictures) so her four friends can fondle it and oogle the size just doesn't really jive with normal feminine behavior - especially when we consider that you claim this is a common happening, which, by the way is also a common aspect of the fantasy. No good imaginary sexual incident is complete without multiple instances. Let's face it, women aren't nearly as interested in dick size as men, and this story radiates male size obsession and the need for female recognition.
Speaking to the very reason for the post - does anybody actually believe that this guy is curious as to whether or not this is unusual behavior on the part of his wife and her friends? Anybody could tell you that it is, and he clearly knows this is the case, so why post about it on a Penis Enlargement message board? It's only tangetially related to Penis Enlargement at best, and it's something that he could very easily discuss in real life, so why post about it here? Obviously these are rhetorical questions as I think that it's clear that he's seeking recognition of the fantasy to complete his fullfilment, another important component of the fantasy process. "Hey fellas, does your girlfriend insist on whipping out your huge penis every weekend so her friends cand stand around and squeeze it? Just thought I'd ask!"
That being said, if it is true, more power to you.