Why are there so many people who oppose racism but are also homophobic?

Homophobia and racism are two different things. Well I don't mind if guys or girls make out. But if any one is gay in my family, I'll be soo ashamed. I have a friend who is gay and I try not hang out with him. But this guy always wants to talk with me, sit next to me hang out with me and its very annoying. I told him it to his face but he doesnt take it seriously and keeps doing it. Call me old school. Well if its OKAY to be gay then it is OKAY to be homophobic. Everyone should respect others' differences. If you can't see that you are blind.