It's an interesting question and undoubtedly one for the scholars of GLBT history. The expression "Coming out of the closet" is idiomatic, of course. I would guess, though maybe somebody knows for sure, that the expression has some kind of literary referent? Though not one that I know of! The whole idea of being "closeted," of course, presumes that there is a "truth" of homosexuality inherently out of line with mainstream culture. In other words, I think I can safely say that most gay people have to go through the experience of "coming out" from presumed heterosexuality into their "real" identities. There's a brilliant but almost unreadable scholar (Eve Kosofsky Sedgwick) who says that the concept of the closet and gayness being within it works to sort of conceptually contain queerness so that ignorance (of, for example, people's non-hetero identites) is justified. She says that there are many different kinds of ignorance and that it's frequently strategic. Can you imagine, for example, what it would be like for straight people to be presumed gay until they made some kind of public showing of their heterosexuality? If knowledge is power, Sedgwick might say, the closet is an open secret.

Just lettin my freak flag fly. I'm sure baypuppy and rhetcompgirl will want to chime on this one!