The fear of being "outed" makes us hypersensitive, both in the kind of situation you describe, and in shopping situations. When we buy panties or a bra, why are we so scared that somehow the sales clerk will figure out our secret instead of just assuming it's for our wife or girlfriend? Why is that so much more scary than buying tampons--obviously the sales clerk isn't thinking, "Aha, this guy must be having his period." Likewise, when we stand up for the rights of crossdressers or transsexuals, why should we fear that people will assume that we must be one? If a white person speaks out in favor of equal rights for racial minorities, nobody says, "Aha, he must be a closeted black guy." In a way, I think your status as a closeted CD or TS person makes your statement in favor of respect and equal rights stronger, since your listeners think that you, like them, are not transgender.
