Tim Wilson, who has reportedly been engaged to Ryan Bolger for nine years, fought back tears as he thanked his fiance for enduring a marriage debate that "has been the soundtrack to our relationship".
"In my first speech I defined our bond by the ring that sits on both of our left hands - that they are the answer to the questions we cannot ask," said the 37-year-old.
"So there is only one thing left to do: Ryan Patrick Bolger will you marry me?"
Bolger, who was sitting in the public gallery, quickly responded "yes" as the floor erupted in applause.
"That was a 'yes', a resounding 'yes'," house speaker Rob Mitchell noted for the record. "Congratulations."
The same-sex marriage bill being debated is expected to comfortably pass through the House of Representatives before Christmas after the upper house Senate last week overwhelmingly voted in its favour.
After more than a decade of debate, Australians emphatically endorsed gay marriage in a recent nationwide postal vote, with some 62 percent of the 12.7 million who took part voting "yes" last month.
Watch the emotional video here
"This is a historic moment of inclusion, of recognition, of respect," Prime Minister Malcolm Turnbull said shortly after the bill was introduced for debate in the lower house Monday.
"This is a day to be especially proud that all of our friends, our colleagues, our neighbours, our brothers, our sisters, can marry the people they love."
Former conservative prime minister Tony Abbott, a leading voice in the 'no' campaign, said he would now back the bill.
"I certainly don't pretend to be an overnight convert to support same-sex marriage but I am pledged to respect and to facilitate the verdict of the Australian people," he said.
"Same-sex marriage should now be recognised. It will now be recognised."
Abbott moved an amendment he said protected discrimination against anyone over their "conscientious view about the nature of marriage", before saying he planned to attend his gay sister's wedding next year.
"I am looking forward to attending the marriage of my sister, Christine, to her partner Virginia some time early in the new year."
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