RALEIGH, N.C. (AP) – A bitter separation between North Carolina’s first openly gay lawmaker and her former domestic partner is converging into a defining case on whether same-sex couples in the state are allowed to adopt.

North Carolina’s Supreme Court said last week it will hear arguments in the custody dispute between state Sen. Julia Boseman and Melissa Jarrell. The two had agreed to allow Boseman to adopt Jarrell’s biological child in 2005 – seeking “two legal parents’’ for the boy – but Jarrell now contends that the pact shouldn’t have been approved in part because the state does not allow same-sex adoptions in which one partner is the biological parent.

A variety of conservative groups opposed to all same-sex adoptions plan to weigh in, and justices have opened the door to allow the groups to file arguments in the dispute. Rev. Mark Creech, executive director of the Christian Action League, said “rogue judges’’ who approved such adoptions have created chaos within the state’s system. He said judges were “legislating gay adoption from the bench’’ while taking the emphasis away from marriage.

“The ruling opens up an opportunity for gay activists to challenge our marriage statutes because our law doesn’t allow these gay couples, who can now adopt children, to marry,’’ Creech said.

State law does not specifically address same-sex adoptions.

But even John Martin, an attorney for Jarrell, believes that same-sex couples can legally adopt a child from a third party. He doesn’t believe that a partner – in either a same-sex couple or an unmarried heterosexual couple – can adopt the child of his or her significant other unless the other person relinquishes rights as a natural parent. Jarrell did not relinquish her rights.

“If we’re to have same-sex adoptions in this type of case, it is an issue for our elected officials to take up,’’ Martin said. “It is not up to the courts to take the legislation and craft an adoption procedure that is not specifically allowed by statute.

It’s not clear whether the Supreme Court will explicitly rule on the same-sex adoption issue, though any decision will have implications for whether gay couples can reach an adoption agreement. A three-judge panel at the Court of Appeals, in siding with Boseman last year, sidestepped the matter by arguing that the couple’s marital status was not important to resolving the case because the two simply agreed on a standard direct-placement adoption while filing a motion to retain Jarrell’s rights as a parent as well.

The adoption decree simply notes that Boseman is a “single female.’’ Lower court rulings have affirmed her right as a parent.

Boseman’s attorneys have argued that the adoption was unremarkable. They noted in court briefs that adoption statutes simply seek the protection of the child’s “needs, interests, and rights.’’ Jim Lea, one of Boseman’s lawyers, said there’s no prohibition in statute’s preventing gay couples from adopting.

“It’s an important issue to us because we certainly don’t want same-sex adoptions invalidated in any way,’’ Lea said. “Any fair interpretation of the statute allows for same-sex adoptions. It absolutely does.’’

Boseman, a Democrat from Wilmington, was first elected to the Legislature in 2004. She has said she will not run for re-election this year.