Considering the age of kid, I would have responded by saying that there will be too many husbands and wives and the uncles and aunts (mothers brother/sisters and father's brother/sisters) will be very few. + there will be a problem in defining grandparents from mother and father side.
It's always best to give a truthful answer that is age appropriate. A five year old is still in a dreamy imaginative state, and so innocent. I would just tell him that it's so sweet that he loves his sister so much and they will always love each other and have a special relationship, and so a brother and sister don't have to get married, because they will always have each other.
Explain to your child about genetics in simple form. When you marry within siblings, you weaken the genes in some way which then causes certain health problems. Google it.
Show him the DVD cover of "The Hills Have Eyes" and tell him it's not healthy.
tell him thats only acceptable in kentucky/tennessee
Are you religious? Then "God doesn't like it." Not religious, hard to say.
because they are family and you can't marry family.
Yeah, the simplest answers are always the best.
Because family doesn't marry family.
That should be easy:
1. They are same family.
2. You need to get to know another family and you will loose that chance if you marry someone in family :)
just tell your kid we dont live in Alabama
Say 'I don't know.'
5 year olds don't understand genetics or why the arrangement is an idiotic idea.
When brothers and sisters have babies, the babies are very sick and don't get better.
Because brothers and sisters are family from the same mommy and daddy, God gave them to eachother to spend the most of their lives together anyways, and because one day when they are bigger they will want someone romantically, and that person will be their husband or their wife who they get to chose to be with for the rest of their lives
Tell him you'll talk about it in 5 years. He'll figure it out on his own by then.