I really don't like the idea of citing this study. It's always this same one from the 90s, and if it were acurate I expect the results would have been reproduced more. It's also not clear that the results indicate what the paper says. There's other reasons than sexual arousal that could explain the results. It could be they're imagining the scenario and are axious or disgusted by it. There's this paper that indicates homophobia is usually caused by fear or hate.

I don't like the idea of putting the blame for homophobia on closeted queer people. It's seems extremely likely to me that most homophobic people are straight, since most people are straight. Also we should respect other people's own identification instead of trying to force labels on people, even if they're bigots.