Until their emotional reveal on The Block finale last Sunday, Sara and Hayden Vale had kept their baby news top secret. But while the couple were keeping mum, their two-year-old daughter Harlow wasn't as discreet and almost blew the burgeoning family's cover!
"We had a friend over and she told us she was pregnant," says Sara, 33, who is 14 weeks into her second pregnancy.
"Harlow was like, 'Baby, baby' and started pointing at my stomach. She's really excited to be a big sister."
The curly haired toddler is clearly over the moon with the news as the NSW family sit down with Woman's Day, repeatedly kissing her mum's tummy and talking to her new baby brother.
And she's not the only thrilled family member. Having always wanted another child, the pair put their pregnancy plans on hold to take part in The Block.
After having a tough time falling pregnant with Harlow, they thought it would be equally difficult to conceive baby number two. But to their surprise they'd only been trying for a month when Sara fell pregnant.
"I was a little bit shocked that it happened that quickly," says Hayden, 45. "There was a lot of practising last time. A lot. I was a little upset I didn't get to practise a bit more!"
Proudly calling himself a hands-on dad, Hayden says the TV reno show more than prepared him for the craziness that will follow when their second child arrives.
"The Block was such hard work and so stressful, and the amount of sleep you missed out on was five times as much sleep deprivation," he says. "So I think that looking after a baby is a piece of cake after that and I'm all for it!"
The stress of taking part in the reality series definitely took a toll on the couple, who admit it wasn't always easy watching events unfold on the show, even while they were privately revelling in their impending baby joy.
But while recent episodes have seen them increasingly isolated from the other Block teams, Hayden says the distance came down to one reason only – their commitment to their own family.
"What viewers don't understand is that every Sunday when all the others socialised together, we went to see Harlow," he says.
"We were so exhausted, but it was like a prize seeing Harlow at the end of the week. We needed to have time with her rather than making sure our friendships with the other Blockheads were as good as they could be."
In the months leading up to their little boy's birth, the couple are going to be busy again. Sara is pushing Hayden to finish work on their new home so they can finally move out of their two bedroom rented apartment.
"It's good to know he's going to build our place faster so we can have a backyard to play around in," she laughs.
And having suffered from terrible morning sickness throughout her first pregnancy, Sara is also determined to enjoy this time as much as possible – and she might not be finished expanding their family yet.
"This pregnancy has been a dream," she says. "I would like three I guess, but for now two is great."
"I was hoping this would be twin boys and then I could have hung my boots up," laughs Hayden.
WATCH: Introducing The Block babies!