I don't have gaydar. I am usually the last to know whether someone is gay. Quite a few of my high school and college friends turned out to be gay, and I never suspected. It wasn't really safe to come out in my home town, especially in high school.
I suspect that my cluelessness has contributed to some awkward situations over the years where gay men have assumed that I was also gay and came on to me. As flattering as this can be, it can also be a bit shocking as when one man planted a big wet one on me out of nowhere. I don't know what signals I was putting out, but nowadays I don't get out much and don't have much of an opportunity to get into "I thought you were gay" scenarios.
I have never been homophobic or concerned that I might be gay. Presumably, I would know if I were sexually attracted to other men. I am attracted to women, so that rules out gay. I don't enjoy gay porn, so that rules out a career in conservative political circles.
One of my conspecifics doesn't want his kids to have gay teachers or to be exposed to homosexuality. He fears that if they find out that homosexuality is an option, they will decide to be gay! He would rather his sons repress their true sexual preferences, if they turn out to be gay, and pretend to be straight, no matter how miserable this makes them. I don't know why he feels this way. I bet he would love his son anyway.