AUBURN – When a male couple who lived together in Lewiston for a decade decided to put a legal end to their relationship, they ran into a roadblock.

In order to terminate their Vermont civil union, that state’s law said one of them first had to live there for at least a year. But no such residency is required to get a license.

Both men live in Maine.

They drew up a legal separation agreement two years after the union, deciding on the terms of their split. No children are involved.

Just one problem.

Maine doesn’t have a simple procedure that allows for the divorce equivalent from a civil union. It doesn’t have a civil union law, much less allow marriage of same-sex couples. Likewise, there is no established process in Maine courts for ending such legal couplings.

So, Jack Keith of Auburn filed a civil suit in Androscoggin County Superior Court against Richard Collette of Portland. Collette agrees with Keith that the court should grant a dissolution of their civil union. That way, any lingering legal liability left over from the Vermont union would be put to rest and the terms of their separation would be legally binding.

Mary Bonauto, a Boston lawyer who lives in Portland, represents Keith. This is the second time she knows of that a same-sex couple in Maine has taken its case to the courts seeking to legally sever their Vermont civil union.

Bonauto stands at the forefront of such legal matters. As an attorney, she pushed for legal civil unions in Vermont and as lead lawyer for same-sex marriage in Massachusetts.

Bonauto also successfully brought the first similar Maine case to Sagadahoc County Superior Court where a judge in November granted that former couple’s requested dissolution of its Vermont civil union.

That bodes well for Keith and Collette, she said.

Although Maine doesn’t necessarily recognize the benefits of their Vermont civil union, both men are eager to formally end their relationship, she said. In his suit, Keith says he is involved with someone else. It’s unclear what legal obligations, including financial liabilities, Keith and Collette continue to have with one another in Vermont or elsewhere.

“That’s what’s at the core of this,” Bonauto said. “They want closure and to be able to move on with their lives.”

In her written argument to the court, she says that Maine’s silence on the subject of civil unions makes it difficult for the couple to legally separate, unlike a married couple, who can file papers in any of Maine’s district courts.

“The parties here have no adequate remedy at law because no statute addresses their situation, that of Maine residents seeking to dissolve a Vermont civil union.”

But, because both men live in Maine, Vermont courts lack jurisdiction, she wrote. And neither Maine’s marriage nor domestic partnership laws apply.

That leaves them in legal limbo.

As with the first case she brought in Maine, Bonauto crafted a legal argument based on two Maine laws.

The first is equity. Whenever no law exists in the state that addresses a specific legal remedy, the state’s superior courts have the authority to grant relief under the umbrella term “equity jurisdiction.” That means the court can fashion its own remedy by creatively cobbling together legal principles and precedent that best fit the specific case in an effort to do justice for the parties involved, Bonauto said.

She cited her earlier case in Bath where the court “exercising its equitable powers, granted a declaratory judgment and equitable relief in an action seeking to enforce the parties’ separation agreement and a dissolution of their Vermont civil union.”

The second Maine law Bonauto cites is one for declaratory judgment. She hopes the judge will order the former couple’s separation agreement legally binding and their union legally dissolved.