I've been saying it for years. Glad I lived long enough to see study after study back me up:

Homophobia is more pronounced in individuals with an unacknowledged attraction to the same sex and who grew up with authoritarian parents who forbade such desires, a series of psychology studies demonstrates.

The study is the first to document the role that both parenting and sexual orientation play in the formation of intense and visceral fear of homosexuals, including self-reported homophobic attitudes, discriminatory bias, implicit hostility towards gays, and endorsement of anti-gay policies. Conducted by a team from the University of Rochester, the University of Essex, England, and the University of California in Santa Barbara, the research will be published the April issue of the Journal of Personality and Social Psychology.

"Individuals who identify as straight but in psychological tests show a strong attraction to the same sex may be threatened by gays and lesbians because homosexuals remind them of similar tendencies within themselves," explains Netta Weinstein, a lecturer at the University of Essex and the study's lead author.
"In many cases these are people who are at war with themselves and they are turning this internal conflict outward."

The paper includes four separate experiments, conducted in the United States and Germany, with each study involving an average of 160 college students. The findings provide new empirical evidence to support the psychoanalytic theory that the fear, anxiety, and aversion that some seemingly heterosexual people hold toward gays and lesbians can grow out of their own repressed same-sex desires, Ryan says.

So don't be homophobic, homophobes, because people might think you're gay. And if you really don't want people to think you're gay, being supportive of gay rights and comfortable with gay people is way better cover than screaming and yelling about the evils of homosexuality. Just sayin'.