I've been wondering about something. EXACTLY the same comments above were commonplace and widespread about the LGBT community years ago. But now, things have changed. In general much of the Western world (which we often tout as being civilized, enlightened, and progressive) has concluded that if sexual acts occur between two consenting adults, it's nobody else's business, we should be open-minded and accepting of the relationship and embrace and celebrate the diversity of humanity.
So in 2013, why is incest still illegal between consenting adults? And given the comments of revulsion in this thread, why doesn't this same enlightened attitude apply to incest in the case of consenting adults (of the same or opposite gender)?
Personally, I think it's only a matter of time before the incest laws are challenged in court and ultimately fall (using many of the same arguments that empowered the LGBT community), and a few years later major corporations will be proud sponsors of "Incest Pride Day".