@Mousa,
J Teeth: I'm honestly not sure that it would be AJ. She could very easily be conservative - she has very clear older family values, and I also have a tendency to stereotype the south - but she still strikes me as remarkably open-minded. If anything the fact that it happens simply wouldn't occur to her.
If it were anypony, I think RD would be the most homophobic. She'd have reason to - she
has to have heard more than a few jokes in her time - plus she simply has the personality to reject it.
The thing about it, though, is that homophobia doesn't
have to be hate. My family is incredibly accepting of me, but my mother and brother are still mildly homophobic. They've told me that the thought of it makes them uncomfortable. That's the sort I'm talking about.
Like, let's say that it is AJ who happens to be the homophobe here. The story could easily be about her trying to come to sorts with, say, Big Mac's sexuality. She
wants to be there for him, and she
wants to understand it, but she can't. It makes her uncomfortable and confuses her, and she may even hate the fact that she's homophobic. The story, then, becomes much about her struggles, why she feels that way, and how to overcome it.