David Gillespie and Nathan Yarnold, who have been together for about 16 months, recently joined a growing social media backlash against Nick and Sarah Jensen's anti-marriage equality stance.

David, 20, and Nathan, 26, have publicly expressed their disappointment over Mr Jensen's first-person piece, "Gay law change may force us to divorce", which quickly gained national attention after it was published in weekly magazine Canberra CityNews on June 10.

The public outcry that has followed included a public Facebook event, "Celebrating Nick & Sarah Jensen's DIVORCE!", on which 180,000 people have said they will attend a mock party.

The page has been filled with pictures and messages supporting marriage equality, including one posted by David last week.

"I don't see how all same-sex couples wanting to marry is any of your business as I believe it should not affect you in any way whatsoever," David, who lives in Dapto, wrote.

"If the day comes where my partner and I decide to get married ... we'll be enjoying our wedding day and not caring at all on whether you are together or divorced.

"Times are changing and you both need to get over it ... I just don't think I'll ever understand your point of view."

David also described how he grew up fearing he wouldn't be accepted for being gay.

"So, I say consider yourself lucky you didn't have to grow up going through hell and being afraid," he wrote.

David told the Mercury he didn't realise how far-reaching his statement would be.

"I just saw their story on how they're doing things and just thought it was ridiculous," he said.

"I know a lot of people out there that haven't come out fully or don't feel accepted.

"I've been through it all before [and] I just wanted them [same-sex couples] to know that there are people out there just like that and there is help."

While Australia's progress on marriage equality was heading in the right direction, David and Nathan said they wanted the government to "really push it that one step further".

"Put yourself in people like myself's shoes. If you love someone and couldn't marry them ... take the time to see how it would make [you] feel," David said of people opposing the change.

"People like me just go through hell all the time, we can't walk down the street holding hands or anything like that, we just can't show affection because it's just not accepted in the way we'd like it to be."