I am afraid I do not entirely share your comparison of our current situation with the situation of the Polish under German occupation - and this causes me certain difficulties to argue against yout theses. Certainly, such an analogy can be made for timeslaps/countries with the worst persecution of gays, but this analogie does not reflect current realities of gays living in more liberal countries.
It is surelly true that gays should not be members in oppressive organizations, e.g. (from my point of view) catholic church or conservative parties, as such organizstions are homophobic by their inner nature. But what's wrong with liberal parties, antifascist movements or simply a orchid growers club? Shall I cancell my membership in any organization with a hetero-majority membership? You couldn't have mean this. If you think about police, military, government and legislation - this might be a controversal question in highly oppressive societies, but certainly not in most todays democracies. Why should we by free pieces surrender the terrain we have conquered in long battles?
The problem which I see is, that you (apparently) assume that most straights naturally belong into the enemie's camp. This is not necessary the case. Not every heterosexual is a homophobe, and therefore qualifies as a potential ally, if offered a cooperation. Surelly, being a purist can be a satisfying feeling by times, but it is not very suitable strategy in pursuing some real improvements of life conditions.
By lucky circumstances, and mostly with an immense effort of persuation and political intriguing gays often enough have managed to pull a widely heterosexual majority into supporting our agenda. This has worked in many countries and proved to be a usefull strategy - the results are amazing, considering that we form solely 10 % of the population. Same-sex marriage legislation in Spain, Netherlands, Belgium and Canada for sure were not possible with cooperation of the heterosexuals - and shows that the "hetero rule" is not necessarily an eternal condition. We also must acknowledge a good will of those hetero politicians, who ventured to risc their own political career by helping us.
We shall form our community and proceed with improving our situation by both means - through our own efforts
and by forming (temporary?) alliances. Of course we must be aware that such alliances do not
*) last forewer, but we should use the possibilities when offered.
It's not about collaborating with the enemy - it's about fighting against the common enemie, namely against the stupid bigots. A mistaken identification of one's assumed enemies can be fatal even on a political battlefield, right?

*) P.S. I corrected a typo here, of course I meant: "...such alliances
do not last forewer..." instead of "...such alliances last forewer...". Beg your pardon.
