'I was homophobic. And then my twin brother came out.'

I was asked a question recently as to when I realised it was important to stand up for those in the LGBTI community. This was a difficult question to answer after hearing so many brave people tell their own stories.

I simply said that the moment you realise your brother considered ending his life, because he hated that he was gay, is the moment we need to stand up and make change.

Now, I am owning my past contribution to the problems associated with the LGBTI community. Enough is enough, and our children need to understand the impact of homophobic words and actions.

The current debate about marriage equality – and returning to my hometown recently – has got me thinking about my youth, growing up in country Victoria. Despite having a fantastic and happy childhood, I haven’t stopped thinking about some of the homophobia I contributed to during that time.

I wasn’t born free from homophobia. Just like I wasn’t born homophobic. But there is no doubt I was definitely a product of what I was exposed to. Growing up, it was common to come across homophobic language, whether that be at school, on the street or on the sporting fields. The word p**f, or fa**ot, was part of my vocabulary.

It is something that I've spoken about before - that I was unfortunately part of a culture growing up that routinely included homophobic language and taunted others. These are not actions I am proud of, and I now regret them.

Looking back, it is quite shocking to think that with a gay twin, who was struggling with his sexuality, I was a homophobic teen.

I am sure my homophobic behaviour contributed to my twin hiding his sexuality even longer.

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When I returned to our hometown, a big part of me wanted to right some wrongs that had happened in the past. It is a horrible feeling to think that my own use of homophobic language growing up was not only used against others, but against my twin brother Lachlan. It's disgusting behaviour with no excuse.

In Lachlan's case, he was so scared of his own sexuality and hated himself so much, that he used homophobic language as a tool to hide his own sexuality and fit in with the macho culture that dominated growing up.

It makes me feel physically sick as an adult, thinking about the impact that my homophobic language and behaviours had on my twin brother.

For those who I used homophobic language against growing up, I apologise as it is only over recent years that I have understood the impact of using this type of language and behaviour. We all make mistakes, and I am willing to admit to mine.

I want to use my experience to make sure others don't suffer from homophobic slurs, don't use homophobic slurs, and can lead happy and healthy lives.

I also want to make sure people understand that attitudes can change. My twin brother's mental health anguish was a direct result of his struggle with his sexuality, and completely changed my view about homophobic behaviour. It made me understand the impact of our words and actions on the mental health of others.

While I can't change what has happened in this past, I am dedicated to changing the future for those who are also coming to terms with their sexuality.

So what changed my mind? The marriage equality debate has made me realise that my past attitudes are still very much commonplace in some parts of the broader community.

Many young people still feel isolated and alone because they feel different.

Many people in the LGBTI community wake up every day, hating the person they were born to be, with one of the major drivers behind this being blatant homophobic attitudes.

Equality will make a huge difference to the lives of young people figuring out who they are and who they want to love. They will be less likely to feel different and alone.

And it is my hope that some of the language used in the past will be completely unacceptable from this point on.

When someone isn’t seen as equal in the eyes of the law, it makes it easier for people to justify the words used and homophobia. This is not fair and has to stop – it's hurting too many people who don't deserve to be hurt.

That's why I'm voting "yes". For the LGBTI community, for my brother, and for all Australians.

Want to get involved in the YES campaign for marriage equality? Visit yes.org.au. And make sure to get those postal votes posted!