Quote: "Have you ever seen a "hetero pride" parade? If you did, would you be offended? If so, why? Why is a person who believes that marriage should be between a man and a woman wrong? I'm not talking about haters or people who are opposed to same sex marriage, but just people who don't think its right. What makes their belief wrong and another right? "
If heterosexuals needed to defend their rights, then I wouldn't find it a problem, otherwise it would just seem to be an attempt to snub gay pride parades or an attempt to belittle them, I can see no other reasons as to why somebody may wish to start one. The whole point of gay pride is to encourage support for gay rights, essentially it's a form of protest. They wouldn't be the first civil rights movement to use parades and it seems to have worked for others, so it seems natural to try the same. It's a peaceful way of standing up for their rights. I am sure once they are accepted by society, they'll move on because their purpose will have been exhausted.
As a heterosexual I feel in no way persecuted in the society I live and nobody will be bothered in knowing that I like people of the opposite gender (except the opposite gender perhaps, they'll prolly run a mile

) and as a heterosexual I have the rights I need. I don't feel the need to hide my sexuality in order to be treated fairly or with respect.
Personally, if a person disagrees that homosexuality is right, I don't have a problem so long as they're not hurting the rights of homosexuals (it fits in with my general philosophy of, "you're welcome to believe what you like so long as it's not hurting anybody), that belief doesn't have to change how you treat people and I know people exactly like that (who disagree with homosexuality, but make no move to prevent it in others or to treat them any differently).
You say, "what makes their belief wrong and another right?" and I think it's a good point, many laws and governments suggest homosexuality is wrong, the problem is that they shouldn't be able to decide that, because at the end of the day, all it'll affect is the parties involved. A heterosexual need not be affected just as a person who believes it's wrong to eat pork is not affected by my love of bacon. If I was denied my right to eat bacon, I am sure I would be marching in a bacon pride parade.