I soon discovered that the farther you exist from a simplistic stereotype of what gay is, sometimes the worse it can be. Gay male stereotypes exist largely to allow straight men to not be threatened by them. The mincing, fem Nancy boy stereotype has nothing to do with a straight mans reality, therefore they can mock and “other” him. With someone who they didn’t know was gay until they were told, that is often too close to home. The “what does that say about me?” question comes front and center.
Beautifully written.

To some extent, I think this applies to all differences between people and the mechanism by which someone comes to be perceived as threatening, disgusting, or just “other” in a more vaguely unpleasant way.

It’s just so jarring for people when someone who they thought was more or less “one of them” turns around and says or does something that runs so counter to the things they assumed were part of the in-group’s core beliefs that they then have to lash out even harder than they would have against this sort of “other” than one who was never part of the group to begin with. Because as you said, the existence of this kind of person threatens their own sense of identity, and some sort of intense, sudden action is then required to alleviate that cognitive dissonance felt by members of the in-group.