To tell or not to tell is a highly personal and complex decision with often profound (positive and negative) consequences. Both sides of the debate have made strong arguments to support their positions. Bottom line is that anyone giving advice does not have to live with the consequences.
I know personally the costs and benefits. I can and do offer personal support and advice to anyone who has to deal with the consequences of discovery.
I must join the protest on this. I will happily share my experiences in going out and the general level of tolerance if not acceptance I find with the public. I do so to encourage those who would like to venture out but are too fearful of reactions. Frankly I don't need others to go out dressed and my agenda is simply to support those who would like to try.
We are all intelligent people - take the experience of others into account and make your own decisions as to whether to tell your SO or whether to go out in public.