bludude, there is a difference between this man's situation and incest. Incest is fucked up, plain and simple. However, look at many other cultures, for example the Berber of Morocco and Angola. The wives are as young as twelve and get married to men in their thirties. This has been going on for centuries and the Berber are happy people. This man's situation is no different. It may seerm strange to us because it is outside what we are used to, but if they actually love one another and the parents are cool about it, what buisiness does the government have in sending the fellow away to prison? That there is three lives ruined. The father gets screwed over for the rest of his life for being a "felon", the girl loses her man and the custody of her child, and the child has to be raised in a foster home. I have a good friend who was raised in foster care and he wishes to god that it didn't happen. He has issues to this day because of that.
People, for the child's sake, let the couple live in peace.
They also have loving grandparents on both sides who are in favor of the relationship, they can help.