Tell me why it's wrong in the case of wanting to be dating or having sex or anything. For the sake of this argument, let's assume that we're not talking about procreation or anything.

Also, "it's gross" is not a reason.

We're not talking about procreation when the only rational reasons involve procreation? The reason it's frowned upon in so many cultures is probably two fold; one it increases the risk of birth defects in offspring and two it decreases genetic diversity.

I just vomitted a little.

The problem is in the relationship between siblings, mother and son, father in daughter, or any other family relationship. More often than not someone in the relationship has power over the other. This leads to the question of, can both partners really give consent?

While I can see that it would usually be the case with a parent/child relationship why would it be so with siblings?

You don't have any older sibilings? Most older siblings are more respected by their younger siblings.. older siblings have a naturel power over their younger siblings.. and my older sister kicked my ass when I was young..

Rationally there should be no problem at all as long as there is no conception.

By the way, I usually do not buy the"Oh my God there is a chance of one controlling the other" like if sex was the top of the ultra-mega-max forbidden and sacred intimate stuff existing in the face of Earth. See, people manipulate each other in a number of ways. In a sense, the TV, internet, your boss, the authorities, your parents, your mate, all of them mentally and physically are able to violate and abuse you everyday in much worse than tricking you into giving sexual pleasure or something like it.

Of course I'm not defending domination or anything here, far from it. Just trying to put things into a clearer perspective.

"It's gross" is pretty much the beginning and end of it if we're tossing procreation out the window.

It just doesn't feel right for me or a great many people, but that doesn't necessarily make it wrong

Wow, shit just got real on VGchartz.

I know very little on the subject, but I would imagine incest between a parent and a son/daughter could potentially be psychologically harmful to the son/daughter later in life. A parents role in raising a child is as a teacher, nurturer and protector. Intimacy on a sexual level is not required.

Incest between siblings is probably frowned upon because of the genetic problems associated with procreation. There's probably not much wrong with it, if both parties are consensual and of legal age. Of course with no chance of marriage or children whatsoever (in most cases I hope), a lasting intimate relationship would probably be difficult to build.