The legal debate wages on for gay parents as to what constitutes a “parent”. Is it biology? Legal status? Or, in the case of many gay and lesbian same-sex couples, emotional attachment? The question is whether the definition of “parenthood” should include people who have played a key parenting role in the child’s upbringing even if not the biological or adoptive parent.

New York’s highest court will soon tackle this issue, according to an article in the Wall Street Journal Gay Custody Fights Redefine Legal Parenthood. The New York Court of Appeals heard argument last week in a case brought by a gay woman seeking visitation rights for a young boy she helped raise. The suit challenges a New York state law that limits the scope of parental rights to those with a clear biological or adoptive tie to a child. These issues are seen more frequently with lesbian couples who were together when one of the women had a child through artificial insemination.

The plaintiff in the New York case argues that “parenthood” should include those who played a key role in a child’s upbringing with the support of a birth parent, even when not connected through biology or adoption.

Opponents say expanding the scope of persons who can seek parental rights could lead to bogus challenges – such as aunts/uncles, friends, teachers or nannies – leading to contentious custody battles that aren’t in the best interest of children.

Also problematic for establishing a broader view of “parenthood” is the U.S. Supreme Court’s decision in Troxel v. Granville. This case established that a biological or adoptive parent has a constitutional right to parent their child without interference from any outsiders. The only exception allows governmental or third party intervention if the parent is causing harm to the child’s welfare. Without proof that a parent is unfit, third parties cannot trample a parent’s constitutional right to parent freely.

Research from the University of California, Los Angeles School of Law estimates that in 2013, 15% of unmarried, same sex couples nationwide are raising children.

The New York appeal centers around the broken relationship of Brooke Barone, 33 years old, and Elizabeth Cleland, 31, who were dating in western New York almost seven years ago when Ms. Cleland had a son through artificial insemination. The two later split up.

Ms. Barone says she played the role of doting parent, cutting the baby’s umbilical cord, and caring for him through bath times, meals and doctor’s appointments until Ms. Cleland cut off contact in 2013. “I was his Mamma B,” Ms. Barone says. “I live for the day I get to wrap my arms around him and tell him how much I missed him.”

Ms. Cleland says the two had a tumultuous relationship and that she stopped feeling safe leaving her son with Ms. Barone. “I look at my son, and I’m the only mom he’s ever known,” said Ms. Cleland, who married four years ago.

Some caught up in legal battles have argued that the sole fact a pregnant woman was dating someone at the time a baby is born shouldn’t penalize her later if no other steps were taken to make the partner a legal parent.

While parental rights can typically be secured through marriage or adoption, for many gay and lesbian couples, marriage only became possible after last year’s landmark Supreme Court decision backing gay marriage. Legally adopting a partner’s child can sometimes be prohibitively expensive, lawyers say, and some couples don’t realize it is even necessary until a relationship ends.

UPDATE: Thank you to LexBlog and LXBN Network for recognizing this post with a Top 10 of the Day award for June 7, 2016! See their blog post about it here: Top 10 in Law Blogs: Cannabis Crowdfunding, Brexit, and Eighth Circuit