The "average" family doesn't always fit into the nuclear definition. Blended families with unwed parents, children born outside of marriage or children from a previous relationship are quite common, and the adults are more than willing to voluntarily take on traditional parental obligations.
What happens when the relationship changes? Under Louisiana law, paternity must be established before a mother can legally force a father to pay child support. What if the father willingly agrees to pay? Should he be concerned with taking a paternity test first?