What is immoral about incest as long as it is between adults consensually?

I was raised non-practicing Jewish. I believe in God but am not of any faith. I believe in choice. For example I am a believer in not pushing your religion onto the law books. I support LGBT and Freedom of Religion. So I don't see why two adults, even if related, can't have sexual relations if they choose.... show more I was raised non-practicing Jewish. I believe in God but am not of any faith. I believe in choice. For example I am a believer in not pushing your religion onto the law books. I support LGBT and Freedom of Religion. So I don't see why two adults, even if related, can't have sexual relations if they choose. So while I would not have sex with a family member what would be wrong if I wanted to? Like my Dad is a widower. What would be wrong, as weird as it sounds, if he and I had father-son sex since I am an adult? Not that I would do that but if a father and adult son wanted to why should we stop them? Why is it against the law? Same with father and adult daughter sex or even marriage.

Shouldn't marriage equality be to all adults? What is wrong with incest as long as we are not planning on conceiving? I know there is the risk to offspring but that is what birth control is for in incest relationships? Obviously I am only talking about adult and consensual relations.
Update: PS---I am only referring to consensual adult relations, of course I fully condemn any child abuse or any rape. Any relation I am talking about is between adults and consensual.
65 answers 65