For Claudia Long, the worst thing about growing up a "Gayby Baby" was the often "disrespectful" questions that people asked.

The 18-year-old lives with mum Susan and her partner Jane in an inner-city Melbourne suburb. The two have been together since Claudia was 11 months old.

"I think one of the most difficult things about being a gayby is that people forget their manners and decide it is perfectly  OK to ask all sorts of questions," Ms Long said.

"People ask me if I missed having a dad. 'What's it like not having a father?' And I am like, 'what's it like not having any manners?'"

The journalism student's dad, Arthur, is also in a same-sex relationship and lives in regional Victoria.

"I don't miss him because he is there," Ms Long said.

"I have a great relationship with my dad and I am really glad to have him in my life. Without him, I wouldn't have had a lot of experiences that I have had.

"Just because I have two mums [the idea that] I am suddenly cut off from everything masculine is ridiculous."

The term "Gayby Baby" has gained a place in the nation's lexicon since Australian director Maya Newell made a documentary of the same name following the lives of four children raised by same-sex parents.

The documentary, which went on general release in Melbourne on Thursday, hit the headlines after it was banned from screening in NSW's public schools.

But Ms Long said "gay families" had always been a reality.

"Gay families and children have always existed and will continue to exist no matter what the conservative commentators or the Australian Christian lobby decides to print about us," she said.

"I feel like it is a waste of time because we are debating what's already a reality [and what's] really not a problem.

"It's sort of like debating whether we breathe oxygen. I mean it happens."

Ms Long said it was "incredibly frustrating" to watch from the sidelines when gayby children were "used as pawns" in the debate about same-sex marriage.

"You are reading the paper and it says 'oh, think of the children'. But we don't get a right of reply," she said.

"What I would like to say to those people is 'stop wasting your time.   You don't really need to worry about us, we are doing perfectly  all right. Just get over it'."

Andy Brewis, 23, was fostered by two lesbian women since he was seven years old.

Yet, he says, he can shave, change a tyre, ride a motorbike and loves cars.

"I find it confusing when people ask me if [having two mums] affected my masculinity," Mr Brewis said.

"If anything, I am a classical Aussie bogan. I drive a [Holden] Commodore and I drink beer and I work in transport."

Mr Brewis lost his father when he was just three. By the age of six, he was forced to look after his partially disabled mother and his sister.

His foster mums, he said, brought normalcy back into his life.

"Things were difficult when I was growing up. I had to take charge," Mr Brewis said. "My foster mums brought my childhood back."

Gayby Baby is showing at Cinema Nova.