The note was snapped by a passer-by and shared on local Facebook group Humans of Eastwood Daily, where it quickly went viral, attracting more than 1200 reactions and 290 comments, news.com.au reports.
Their son, Brandon, 18, told The Daily Telegraph he was shocked to see what his parents wrote about him.
"I wasn't expecting that … I thought, 'What the hell?'" Brandon said. "I think I am a catch."
Mrs Lim said the note was intended as a joke with her customers and didn't really want her son, who is in his first year of a business degree, to move out of home.
The family has run the same business for the past 25 years and said they often joked with customers.
"Eastwood is becoming part of our family so we always joke around," Mrs Lim said.
Julianne said her parents owned the business before she was born. She joked the whole suburb knew she was getting married.
"My parents opened the bakery the year I was born and some customers have watched me grow since I was a baby," Julianne said.
Lims Hot Bread reopened earlier this month after the short closure.