Despite rumours of their relationship starting in January, the 37-year-old has never confirmed Peter to be her boyfriend. And this is the first time she has shared him on her socials.
They were first spotted together in Melbourne in January, then again in April.
Reportedly now a model, Peter used to be a footballer in NSW.
Nadia shares two children, Aston, six, and Henley, three, with her former husband Jimmy Bartel.
The pair were together for 11 years, married for five, before announcing their split in 2019.
Nadia has previously spoken about wanting to have more children.
WATCH: Nadia Bartel admits she's struggling with parenting during pandemic. (Article continues after video)
"Always thought I would have a few more, but who knows now... I'll let the universe do it's [sic] thing. I am also so damn lucky with the two I have," the mum-of-two wrote on Instagram.
Nadia's relationship Instagram debut comes over a year after her infamous white powder scandal in September 2021.
At the time, a video emerged of Nadia and a group of friends flouting Melbourne's lockdown rules, with a plate of white substance.
The former WAG issued an apology regarding the leaked footage.
“I have let you all down by my actions,” she wrote. “I take full responsibility and I am committed to taking all necessary steps to ensure I make better choices in future.
“To my family and friends, my business partners and the public health workers trying to keep us all safe, I am embarrassed and remorseful.
“I am truly and deeply sorry. I hope I can earn your forgiveness and, in time, your trust,” she finished.
Nadia and her involved friends were fined $5,452 each for the breach of the public health order.