"I think my friends are a little jealous, because I've got two mummies and two daddies and they've only got two parents," says Simon, 6, squirming with his brother Joaquin, 3, on the knees of their four gay parents.
While Britain and France in the last week plodded ahead with gay marriage draft legislation, the first country in the world to legalise same-sex unions, the Netherlands in 2001, is already one step ahead.
The Dutch justice ministry is about to commission a report examining the possibility of recognising three parents or more for one child, notably to protect so-called "pink" families.
Legally speaking, while Simon and Joaquin have four parents -- Joram, Guillermo, Karin and Evelien, all in their 30s -- only the two women have the right to call themselves parents.
The two men cannot take major medical decisions for the children, and if the men die the children do not have the usual inheritance rights.
If the couples were to have a bust-up, Karin and Evelien would have the right to demand that Joram and Guillermo no longer play any role in the boys' lives.
"The law is lagging behind reality," said Joram. "What counts, as a parent or future parent, is wanting to raise children within a framework in which you have enormous trust."
"Of course, you want to be recognised for everything you do for your child," Guillermo said, during a family walk along one of Amsterdam's canals.
"Having children changes your life."
Joram, Evelien, Guillermo and Karin were flatmates during their time as students in Amsterdam and the two couples remained friends afterwards.
When they wanted to have children, they decided to do it together, themselves rather than as two couples seeking adoption or a sperm donor.
"We wanted the children to know their parents, their mothers just as much as their fathers," said Evelien.
Her partner Karin, a doctor, recounts how the children were conceived at home through DIY artificial insemination.
Evelien and Karin each gave birth to a child, one fathered by Joram and one by Guillermo, but the family doesn't want to reveal who are each child's biological parents.
"That's unimportant, what matters is that we're all four of us their parents and that we love them," said Karin.
The children spend the week with their mothers in the eastern city of Arnhem, where the two fathers come every Thursday to look after them.
Weekends are spent as a family of six, often in Amsterdam, in Joram and Guillermo's flat.
Holidays are also spent as a family, as are birthdays or parent-teacher meetings at Simon's school.
Changing the law on parenting would not only benefit "pink" families, but also divorced parents who marry someone who takes on the role of parent," said Green lawmaker Liesbeth van Tongeren, who tabled a parliamentary motion after which the ministry agreed to investigate.
"We need to broaden the concept (of what is a family), no longer can you see parenting as a purely biological link or say that a child can only have two parents," Van Tongeren told AFP, saying there are between 20,000 and 25,000 children living in "pink" families in the Netherlands.
Junior Justice Minister Fred Teveen, however, said at a debate in parliament in October there were potentially many practical objections to changing the law and that he would await the report's conclusions.
Philip Tijsma, spokesman for the world's oldest gay rights group, COC, said: "You won't solve all the problems, there will always be conflicts."
"But in any case there will be some security for the child, because they'll know that their father or third mother can't just disappear from their life one day to the next," he told AFP.
As for Simon and Joaquin, they appear very pleased with their family.
"One day, when Joaquin was at the creche, two girls wanted to play and they both wanted to be 'mummy'," said Evelien.
"He said 'fine, we can do that, I have the same thing at home'."