I don't think you owe it to yourself to come out and tell them point-blank. You know what your indentity is, telling or not telling isn't going to change it.
Where there is a chance for uncomfortable surroundings, maybe leaving it alone is ok? You're not "lying", you're just realizing that not everyone needs to know everything about everything. Some people's spheres of happiness depend on some consistency... and if you pop their happy-bubble, you're only creating problems which may (as soemone else pointed out) outweigh the benefit garnered from outing yourself.
Good luck, lurkette. We love ya.
