Ah, I bet I got your attention with that header! Anyway... Let's say a brother and sister were to have sex. It is completely consensual and they had no regrets afterwards. Assume the sister is unable to become pregnant. Given those parameters, is incest still wrong? How so? Before you all start flaming me, know that I do not condone incest. I have never done it nor do I encourage anyone else to do it. I just find this question interesting.