How do you know if you have homophobia?

A "phobia" is an irrational fear. Homophobia is the irrational fear (and usually dislike) of homosexuals. It is usually caused by the person's actual fear that they might be gay. People who do not worry whether they are gay or not are usually willing to let other people do whatever they want with their own private lives.

By definition, if you are afraid of someone being gay for irrational reasons, you are a homophobe. However, if you merely believe it to be immoral, you may still be referred to as a homophobe, which may be confusing because the disapproval of homosexuality is not the same as the irrational fear of homosexuality.

So, one way to put it: if you have a fear of homosexuals that cannot be explained, you are a homophobe. If you disapprove of homosexuality for some sort of reason, you may still be referred to as a homophobe, even though you are not necessarily "afraid" of them, much less irrationally afraid.