Schools and early childhood centres are being warned to teach kids more about same sex families, or risk causing long-term harm.
A Wellington trio is also hoping to improve the lack of resources in New Zealand classrooms depicting gay and lesbian characters.
"Love is between more than just a man and a woman," co-author Adam Reynolds said, who is helping write a children's picture book where the two main characters are gay.
"The story shouldn't be the sexuality the story should stand on its own," fellow co-author Chaz Harris added.
The friends said they grew up questioning whether being gay was wrong because same sex couples were never featured in their childhood.
Experts also say resources showing diverse families are vitally important for children.
"We know that if a child's family is rendered invisible that the child is harmed," Jannette Kelly, who lectures professional studies in education at Waikato University, said.
Last year the Ministry of Education introduced new guidelines for sexuality in the classroom, but schools still decide what resources they purchase.
"I think the key thing to remember is I was exposed to 99.9 per cent heterosexual stories growing up and it didn't make me straight," Mr Harris said, who continues to fundraise for his book.