I have a homosexual question and incest question?

[Dystopia]

Imagine if every contry accepted homosexuality, and i'm not against it though because most of our values are based on greece democracy (With a little reactionary religion like christianity in the mix).

Now thats all good.

But...

What if brother and sister loves each other so much that they want to get married and live the rest of their life with each other, imagine incest parade where they are proud to be together.
Of course there will be a law where they cant create babies with each other otherwise it will be genetically bad, so they will adopt.

Now if that was set. If there would have been a vote poll for "Yes" or "No" for incest marriage.

What would you have answered?

I accept homosexuality and same sex marriage

Incest? I would never bang my sister and I don't support incest, it goes against my family values. But if siblings or father/daughter son/mother want to be in a relationship, so be it, it's a shame it still gets you jail time in some countries. As for incest and marriage, I think any cousin, second degree cousin and so on should be able to get married, I don't have any objection to those relationships, my girlfriend's grandparents are third degree cousins. As for first degree family relationships, the problem is procreation, as far as I know, there is a higher chance that there will be complications and it's impossible to legally ban these people from having children, how would we enforce it? And punishment? would we punish people for getting pregnant? I don't know. As for marriage, I don't understand why siblings would want to marry, but since it's their call, they can get married, just don't ask the church to do it. The problem is if this type of marriage incentives people to have kids, but I guess since siblings can live together in a relationship it's the same... It's like gays, why ban gay marriage and allow gay people to live together? It's just a legal recognition, nothing more