Rotorua-based Waiariki MP Tāmati Coffey is expecting a baby with his partner Tim Smith.
He announced the news at Auckland's Big Gay Out this afternoon.
"I wanted to seize this opportunity, at the biggest gay event in the country right now, to share the news that me and my partner over there are expecting a baby in July," he said as the crowd erupted into applause and scattered screams of excitement.
Coffey, now 40, said it [the baby news] had been a long time coming.
"If ever there was a perfect time, I think now is a really good time," he said.
"I hope that I get to celebrate that with all other kinds of modern families out there."
Before revealing the news, the Labour MP told the crowd "What I love about Big Gay Out is this is a day where we all come together, all types of people under the rainbow umbrella. And it's a beautiful thing. We have all kinds of modern families going on and represented here today so I applaud that."
Prime Minister Jacinda Adern said The Big Gay Out was a chance to celebrate together "but also talk about the things we are yet to do together."
When she introduced Coffey, she joked, "no one knows who that guy is, right?"
After the baby news, Ardern thanked the crowd and said "what better announcement than that?" as the Labour team left the stage.
Coffey, a former TV host, proposed to Tim Smith between Christmas and New Year 2010, in Rotorua.
They became civil union partners in 2011, and have since opened bars together in Eat Streat, Rotorua.