The Internet has been all agog about the declared intention of an 18-year-old New Yorker to marry her biological father, to whom she had lost her virginity two years previously. New York is notoriously liberal on many issues, and has even legalized the marriage between a half-uncle and niece, whose shared sanguinity is estimated at 1/8. But a marriage between a father and daughter is stretching a point a bit much.
Incest is frowned upon not only because of social taboos but because offspring of closely-related individuals tend to have health or other genetically-associated problems.
Laws on incest in the U.S. vary from state to state. In New York, cousins are allowed to marry, for example. However, a marriage between a father and daughter is not legal anywhere in the US, and in many states sexual relations between persons of first-degree sanguinity (father-daughter, mother-son, between siblings) is a criminal offense with sanctions ranging from one year to lifetime imprisonment. In New York, sexual relations between a father and daughter is a Class E felony, which is punishable for up to 4 years in prison.
But the barely-adult woman pointed out that an incestuous relationship between two adults is legal in New Jersey (it is), which is why they moved there. They still can’t get married legally, but she stated in the interview with New York Magazine that “I don’t believe you need a piece of paper to prove that you want to be with the person you love.” They intend to have children. The couple maintains their anonymity for obvious reasons.