The idea for getting married was partly Kevin's idea.
The 11-year-old also thought it would be neat if daddy and papa tied the knot on the same day the couple met 15-years earlier on a softball field.
So Peter Mercurio -- papa -- and Daniel Stewart -- daddy -- started planning.
"I was walking Kevin to school one morning," Mercurio said, explaining to his son that he did not know yet who would conduct the ceremony, or where. And he said, 'Don't judges perform ceremonies? Why don't you try to contact the judge who finalized my adoption?' I said that was a great idea."
In Manhattan Family Court last July, with a few friends and family present, the state affirmed what the three guys had known instinctively for a long time: they were a family.
Their story comes as the U.S. Supreme Court gets ready to debate on Tuesday and Wednesday the issue of same-sex marriage -- the legalities, the politics, the social implications.
It is a personal narrative, though no less important -- than trying to figure out the meaning of the Constitution and the limits of "equal protection."
A day old and abandoned
"I found a baby!" Stewart's voice was frantic, and the echoes from the A/C/E subway station on Eighth Avenue only added to the initial confusion. "I said I had called 911, but I didn't think they believed me."
"I told him I didn't believe it either," said Mercurio.
But he rushed to the scene and to a remote area behind the turnstiles. There, wrapped in a dark sweatshirt, lying quietly, was a brown-skinned, day-old infant. Abandoned.
They could have walked away, but they stayed.
Authorities soon arrived and took the child, naming him Daniel Ace Doe -- for the man who found him, the subway line, and the sad anonymity.
The story made news.
A few months later, Stewart was called to testify in family court about.
The judge dropped a bombshell: "Would you be interested in adopting this baby?"
The answer was an immediate yes.
But Stewart privately knew it would not be easy. His partner at first wanted to go slowly, or not at all.
"My first reaction when I heard: 'Are you insane? How could you say yes without consulting me?'" said Mercurio, laughing at the memory.
The couple had been together three years but their careers as an aspiring playwright and social worker took precedence at the time.
Becoming parents and strengthening their bond was never discussed.
"I saw this opportunity here, this gift to be parents to this child. And how could we not say yes to that opportunity?" Stewart said told CNN Justice Correspondent Joe Johns. "It seemed like it was divine intervention -- it was meant to be."
"I think a lot of my initial response to Danny -- saying we were not ready to do this -- was all fear-based. And once I got over that, a calm set in. And you know, we went about methodically, preparing our lives for a child."
Crib and blankets just before Christmas
It was a mad scramble to get ready, parenting classes, crib, diapers, and blankets. Then just days before Christmas, they were told the baby would be transferred to their care.
"Our paternal instincts took over and it became a natural thing of how to take care of him," Mercurio said.
They took their son home on a snowy day, riding the same C train where they found him.
As blessed as they felt, the couple knew there would be challenges.
When they first held the boy -- whom they soon renamed Kevin -- at the foster home they found him guarded.
"In fact when we saw him he didn't blink. His eyes were just wide open and his arms were very stiff and tightly crossed across his chest," said Mercurio.
"So we got him in this condition and we thought we just need to love this kid immediately," added Stewart. "So we played with him and build up his trust in parents. Build up his trust in adults -- that he could be cared for, nurtured, and loved. So we showered him with love and touch. Didn't take long. He loosened up."
CNN is not identifying Kevin by his last name or his picture, to protect his privacy. But he knows the story of his discovery.
A quiet family life
Mercurio and Stewart created an illustrated child's storybook, dramatizing the events-- from the subway to meeting his new family.
"One day he asked me: Dad is the story about me?" said Stewart.
"I was very happy," said Kevin.
He likes sports, his school, and his friends.
The family went back to the dark underground station. They were all a little nervous about how Kevin would react.
"I think that was important for him to see and know that because now he has a connection," said Stewart. "I mean it's not just something abstract. He really has seen, and knows, and understands. And he has taking a lot of pride in that spot. That's his station. That's his place. This is where we became a family."