This is an interesting question. I look at incest and pedophilia as objectionable, but if you really think about it in the same way as you would homosexuality, as long as no one is being hurt, shouldn't it be okay?
Will there be a huge cultural revolution in 20 years about incest equality. In 60 years for age equality? Will I be on the dark side of history for these, being looked at as a bigot? Who knows.