Credit: Kevin Winter/Getty Images

When Woody Allen married Soon-Yi Previn more than 20 years ago, the scandal that engulfed the couple was enough to stain the reputation of a director as august as Allen. Not only was Previn 35 years Allen’s junior, she was the adopted daughter of Allen’s longtime partner, Mia Farrow. Moreover, Allen admitted to a relationship that began with Previn years before their marriage, at a time when Previn was barely old enough to purchase alcohol.

But under New York law, Allen and Previn’s marriage was perfectly permissible. Now that Allen is back in the news – the 80-year-old director’s latest film, Café Society, premieres in July – it’s also time to revisit whether state laws have kept up with changes in family demographics. The circumstances surrounding relationships like Previn and Allen’s are not so rare today.

Since Previn and Allen’s marriage 20 years ago, the share of “blended” families has risen dramatically. Today, more than 5.3 million children live with a biological parent and their parent’s new spouse.  In addition, more than 2.3 million children live in a “stepfamily” in which the child’s parent is not married to the new partner but is cohabiting.  The rise in multiple partner fertility means that many children (like Previn) have a parent (like Farrow) who has a child in common with a new partner (like Allen), but the adults never marry or cohabit.

New York law permitted Previn and Allen to have sex and marry because Previn was not Allen’s biological child. States with laws more restrictive than New York’s would not have barred the relationship either. Previn was not Allen’s adopted child, nor was she his stepchild because Woody Allen and Mia Farrow never married.  Allen and Farrow never even cohabited.  They were reputed to have separate apartments that faced each other, with Central Park in the middle.

Allen, however, was the father of Previn’s half-siblings.  Allen and Farrow were parents to a biological child (originally named Satchal, but later called Ronan) and to two adopted children (named Moses and Dylan). Allen and Previn’s relationship fell between the cracks of existing incest prohibitions. It also avoided the general prohibition on marriages in violation of “natural law” because that quaint concept predates today’s diverse households. As a result, Allen and Previn could marry in Italy, and their marriage received recognition in New York.

Some readers may be asking “why should the law prohibit the Allen-Previn marriage?” After all, shouldn’t two consenting adults be able to enter the most “profound” of unions, as Justice Kennedy called marriage in Obergefell v. Hodges? Without marriage, would their two adopted children have found a home? Or at least one as a comfortable as their abode on the Upper East Side (which was featured in Architectural Digest)?

Obviously, schadenfreude is not a sufficient reason to call the Allen-Previn marriage “incestuous.”  Nor should we condemn it because we fear for their offspring.  This Jewish movie director and this Korean-born woman are not genetically related. Nor should we use Dylan Farrow’s allegations that Allen sexually abused her when she was seven years old as a justification. Allen vehemently denies those allegations, and he has never been convicted, let alone charged.

Nonetheless we can—and should—condemn such a relationship, and relationships like it, to protect all children. Children in the home should not be potential future marriage partners.  Some states already bar intercourse and marriage between an adult and his or her stepchild for this very reason, even though the two are not biologically related and are both adults when the prohibited conduct occurs. Margaret Mead once warned, “Where the more broadly based sanctioning system has broken down, the household may become a setting for cross-generational reciprocal seduction and exploitation, rather than fulfilling its historic role of protecting the immature and permitting the safe development of strong affectional ties….”

Even the relationship between “consenting” adults can be tarnished by coercion if its genesis was one person’s childhood home. A bill currently pending in New Jersey would criminalize consensual incest between a parent and an adult child.  Former assemblywoman Mary Pat Angelini correctly noted, “Incestuous relationships…are often times sexually abusive relationships blurred by the ‘consensual’ loophole.”

A bright line would render irrelevant Allen’s claim that he never acted as a “father figure” to Previn. Incest laws are applied without attention to such situation-specific factors.  People aren’t left to guess, and debate, where the lines should be drawn. That is as it should be, for only considerable psychoanalysis might determine whether Previn ever saw Allen as a father figure when their relationship began. Allen has subsequently acknowledged that his marriage to Previn was a success because of this “dynamic” during the marriage: “I was paternal. She responded to someone paternal.”

People do not always have the self-awareness or self-restraint that they need to make wise choices, especially when their biological urges are pulling them in a particular direction. During custody proceedings with Mia Farrow, Allen said that he didn’t see his relationship with Previn as “sleeping with [his] children’s sister.”  The law should have told him otherwise.

Simply, the law should prohibit sex and marriage between two people if one of the parties has a child in common with the other party’s parent or if one of the parties is cohabiting with the other party’s parent.  Such a law would have covered the Allen-Previn situation.

The law should also prohibit sex and marriage between siblings, broadly understood.  Statutes often prohibit relationships between half-blood siblings, but they sometimes leave step- and adopted- siblings unregulated.  Today hundreds of thousands of children live with a half-sibling or an adopted-sibling. In addition, children who are unrelated by blood, marriage, or adoption often live together because their parents cohabit.

No one knows if new incest laws would deter more predatory behavior. Sex with a child is already against the law, and incest taboos are not always successful.   Nonetheless, without express prohibitions and bright lines, popular culture will validate the Previn-Allen marriage, adults will be left alone to judge the propriety of their own romantic interests, and more children will experience a reality that reflects Dylan’s allegations.

We can see Woody Allen and Mia Farrow’s relationship differently when we label them as “family.”  When two adults have or adopt a child together, their lives become intertwined in a way that has implications for them and their children.  With 40 percent of all births occurring outside of marriage, and with half of those occurring to non-cohabiting parents, and with high rates of multiple-partner fertility, society must start revising the law to serve children in these families well.

Merle H. Weiner

Merle H. Weiner is the Philip H. Knight Professor of Law at the University of Oregon School of Law. She is the author of A Parent-Partner Status for American Family Law (Cambridge University Press 2015).