The fan favourite has revealed the baby is due later this year.

The Block's Scott Cam / Robby and Mat.

The Block star has announced they’re expecting their first child. Photos: Channel 9

Two weeks after The Block’s Emma and Ben announced the birth of their son, Bailey Colter Cox, another one of this year’s contestants has revealed that they are expecting their first child. Mat, who is competing alongside his best friend Robby, shared a sweet Instagram video on Sunday evening telling his family that he’s going to be a dad.

The clip shows the 41-year-old hairdresser giving a shopping bag to his mum, dad, and sister, and telling them that they will have “no idea” what he’s about to say. His family then pulled out a blue baby onesie from the bag as he revealed his baby boy is due on December 18.

“I’m having a baby! You’re going to be a granny, and you’re going to be an aunty!” he excitedly told his mum and sister.

In an interview with New Idea, Mat revealed that he and his good friend, Leah Cocks, plan on co-parenting their little one.

“I have always wanted to be a dad, especially in this later part of my life,” he shared.

The road to pregnancy

The pair, who met 20 years ago when Leah came into Mat’s salon, shared that the road to pregnancy wasn’t a quick and easy process.

They experienced seven years of medical roadblocks before Leah found out she was pregnant after a round of IVF during the first week of filming The Block.

She then waited until Mat was home in Adelaide to tell him the exciting news, at which point she was already three months pregnant.

“I wouldn’t have done it with just anyone. It’s only because it’s her,” he said.

The Block's Robby and Mat.

Robby and Mat are best mates from Adelaide. Photo: Channel 9

‘Another Block baby!’

Mat’s post has since been flooded with supportive messages from his friends and co-stars, including The Block host Shelley Craft.

“Aaaammmmaaazzzzinnggg NEWS!!!” she wrote alongside two red hearts.

“Hair daddy is gonna be an ACTUAL DADDY!” one follower replied, while another added, “Another Block baby!”.

Mat’s co-star Alicia also reposted the news on her Instagram Story to express her excitement.

“SURPRISE!!! I’m so f**king excited for my Block bestie,” she wrote. “You’re going to be the most amazing Dad! We can’t wait to meet our new little mate!”

The announcement comes shortly before The Block teams take their houses to auction on Saturday, October 25, which will air on Channel 9 the following night.