I must say I'm a guy that has been separated from my three half-sisters due to divorce when I was really little, and never grew up with them. So in the past couple years of being reunited with them, I've found a major emotional and physical attraction to them. I have slept with the oldest one on more than a few occasions consensually. Her and I'd even talk about moving to a country where marrying siblings was legal.
At any rate, I've never understood why people have to use the one-and-only "genetic code and birth" excuse when it comes to the justification of having incest being illegal. Saying that, when there's plenty of preventive measures to not have offspring is just downright unobservant.
We've all grown up in different circumstances and households. I feel those who haven't had the benefits of growing up in a full household, shouldn't be restricted from their feelings or disgraced because of it. The way I see incest in my case, it's not only the missing Westermarck effect, it's all the years of missed support and love (me being the one and only older brother).
Lastly, I also wish I didn't have these feelings sometimes, but I do. It is disheartening because of society, and also something of which you doubt the family would be supportive in.
Anonymous appears to be experiencing Genetic Sexual Attraction. Notice that the problem cited involve dealing with disapproval from others. Why should prejudice and bigotry interfere in consensual relationships?