It comes following the loved-up duo revealing that they were expecting their first child together back in August.
In an Instagram post, both Mark and Bianca shared the news with a sweet photo of them together on a cliffside, with the words "baby coming soon" drawn out in the sand in front of them.
"So… this is happening!!," Bianca captioned her post.
"Excited & maybe just a little nervous for all the new adventures 2022 will bring!!!
Mark also shared the photo to his own Instagram and wrote: "+1 on the way..super excited for 2022 and adding a new member to our little gang.. #duefeb."
Mark, who was paired with Ning Surasiang on MAFS' sixth season, and Bianca, who appeared on The Block in 2018 alongside her friend Carla Dziwoki, met online after messaging one another on Instagram in 2019.
Bianca's first message to Mark was about his stint on MAFS, where she told WHO the first thing she said was: "I can’t believe you did this show."
After a few months of dating, Mark and Bianca took their relationship to the next level and moved in together in Melbourne.
"I moved into Mark's with two suitcases of clothes and that's it so I'm still rummaging through those two suitcases and learning to live a very minimalist lifestyle!" Bianca joked to WHO at the time.
The couple have been relatively private about their relationship, with Bianca previously telling the Herald Sun that most people probably had no idea they were dating.
"A lot of people wouldn't know we've been together for a year because we were so conscious of keeping it on the down low," she admitted.
"For us, it was a real relationship and nothing to do with TV. Even though I'm a public person I've always kept my personal life private. But now we're like whatever, it's going well and really cruisey."
Congratulations to the happy couple!