But Jeremy and Jonathan's parents Travis and Chan-Feng absolutely adore their family.

"Being fathers - we'd have to say it is amazing, but also tough," Chan Feng said. "Getting up to do night feeds when they were little, and at all hours when they are sick."

Before their two bundles arrived as newborns the couple undertook close to two years of planning and research on becoming parents through surrogacy.

"We were the last wave before Thailand stopped," Travis said. "We were very lucky. We were pregnant first go, whereas some families go through numerous cycles of IVF."

On Father's Day Sunday the couple are heading to a relaxed brunch with a group of families with similarly aged kids.

Travis said looking back on their journey as parents it had been a wonderful blur, but the pair promised each other they'd spend their 10 year anniversary later this year dining at Tetsuya's.

Chan-Feng, a GP by day, said he felt blessed to live in Canberra and to have the opportunity to be a father in a same-sex relationship.

He said some of the things said so far in the marriage survey debate had been very hurtful to rainbow families, especially children.

"For adults, we can switch off," he said. "But I believe it is actually quite harmful to children's mental health all this misinformation from the no campaign."

The 2016 Census counted 46,800 same-sex couples across Australia.

However, this data is limited, as it does not include those in same-sex couples who are not usual residents of the same household, or those who didn't put themselves down as either defacto or married.

Of that number female same-sex couples made up just under half, 49 per cent, however, they were more likely to have children than male same-sex couples.

While one-quarter, 25 per cent, of female same-sex couples had children, 4.5 per cent of male same-sex couples had children in Australia.

Same-sex couples accounted for 0.9 per cent of all couples in Australia, up from 0.7 per cent in the 2011 census.

The ACT had the highest proportion of same sex couples of all jurisdictions.

Same-sex couples accounted for 1.4 per cent of all ACT couples, 1.1 per cent of NSW couples and 1 per cent in Victoria.

Archie Clements and his partner were married in Spain and begun their family in 2010, settling in Canberra.

Their seven year old twins, Rufus and Jasper, spent this week busily creating cool Father's Day cards at primary school.

"Their presents are mainly art and they've written us some beautiful letters," Archie said. "It's a really special day for us. It's really nice for our kids to have an opportunity to express how they feel about us, because we express how we feel about them all the time."

The Clements family felt welcome and supported through their school and the wider community.

But as the twins grew older they were more tuned into messages about marriage and family trumpeted through the "yes" and "no" campaigns.

"It's a year where we feel we really need to hunker down as a family and protect our children," Mr Clements said.

"There are a lot of things being said about our families, good things and bad things."

"We hope all of this gets resolved really before the boys start dwelling on it. We want them to take all of that stuff for granted so we can get on with our lives and they can feel secure and welcome within our community."

What had been heartening throughout the tricky period was seeing the Australian community at large pushing the issue.

"People recognise the way you treat one minority group really reflects on the entire society," he said.

"I certainly don't think LGBTI people are fighting this battle on their own."