The group is a group of transvestites and admirers who meet regularly to realize fantasies and just do what they find most exciting. in this group members interact as a group and as individuals, so they exchange pictures and contact details for private encounters.
This is nothing particularly special, since every interest lead people to assemble and share ideas to give that interest some growth. What makes this kind of group special is that they make patent a sexual orientation and a lifestyle, which do not have to go together.
Creating tags and create a stereotype under those tags is quite social, maybe human. We have learnt to judge quickly depending on race, appearance and many other possibilities, although it is possible to not learn or unlearn that, most of the people do not care about learning not to judge and depend on stereotypes. As a straight man said after the explanation of the differences between gay, transvestite and transsexual, "(straight people/men) do not care about that, they are all homos".
This is the issue for every man experimenting with his sexuality and and the sex with other males. After we had some light play, a straight guy (with girlfriend) said to me: "So, you think now I am gay". Of course, I do not think he is gay. At least not now. He is happy now having a relationship with a female, that makes him straight whether he likes or not having sex with males.
Same thing would apply to males who like to be penetrated anally with a dildo or a strap-on. It is quite possible to be a straight male and liking having his ass worked whether it is by a male or a female, as long as his lifetime partner or main interest goes towards women. Proof of this is the number of women who declare experimenting with other women at a point in their lives and have happy straight relationships.
I do not find appropriate anymore to classify lifestyle and sexual behaviour in the same space. Lifestyle is much more obvious because of the partners you have in social events or just in life: you like having boyfriends, girlfriends, both (e.g. straight, bisexual, gay). Sexual behaviour is much more private, particularly for those whose sexual behaviour do not match their lifestyle stereotype, for instance, and going back to the first examples, straight men who like sex with others than women.
This may give much more combinations as expected, as it could be considered gender (male, female, m2f, f2m), relationship status, 'transvestite status' (as some women like dressing as men, just as some men like dressing as women, but it is socially appropriate for women), just to mention the most usual.
In this way it is possible to be a married straight transvestite man who likes sex with bisexual women. Or a more usual one, a married straight man who likes pre-op m2f. This leaving aside roles that may make it more complicated.
It is important to be aware of all this diversity whether or not (hopefully not) we want to grant tags to every situation to learn to dismiss stereotypes. Before that, every one of us will be just like that man who thinks that everyone who is not straight is a 'homo'.