By STEPHEN JOHNSON, ECONOMICS REPORTER FOR DAILY MAIL AUSTRALIA
'I love my darling son/daughter, but I do wish they would just move out...'
It was once so taboo that few parents would dare to say it out loud - but this complaint is becoming more and more common among the elder generations.
While parents of 20-somethings understand the difficulty of the housing market - and the clear benefits of having adult children live rent-free at home while saving for a deposit - they also aren't immune to the challenges of having their kids still living in their back pocket long in their twenties or even thirties.
This frustration is backed up by statistics: cash-strapped parents - many of whom left home at 18 and never looked back - are spending thousands more on food, water and electricity bills just to house their adult children during a cost-of-living crisis.
Unaffordable housing and a rental vacancy crisis means Millennial and Gen Z Aussies are living at home for longer - and it's costing long-suffering parents $4,700 a year.
Australia also has some of the world's most expensive housing compared with incomes, which means those with full-time jobs are living with their parents for longer hoping to save up for that 20 per cent mortgage deposit.
A majority of young men aged 18 to 29 are still living at home with their parents, with 54 per cent in this situation compared with 47 per cent of young women.
Younger people are increasingly still in the family home because moving out is simply too expensive, the University of Melbourne's Household, Income and Labour Dynamics in Australia survey of 17,000 people found.
Cash-strapped boomer parents are spending thousands of dollars a year extra on groceries, electricity and water bills just to house their adult children during a cost-of-living crisis
Professor Roger Wilkins, a social researcher, says more younger people are now going to university, leading to a delay in reaching typical life milestones.
'We've seen a rise in higher education participation, declining full-time employment opportunities for young people, a rising cost in housing, and a trend towards later marriage and family formation,' he says.
'The traditional markers of adulthood are happening later in life now.'
Finance author and mother-of-two Nicole Pedersen-McKinnon warns the cost of keeping adult children at home could be financially catastrophic for parents.
'It is a real danger - a complete cash catastrophe or what I call a "cash-astrophe",' she tells me.
Nick Tebbey, the national executive officer with counselling group Relationships Australia, also says tensions between parents and their adult children still living at home can potentially cause permanent damage to the relationship.
'Like any tension that's left to fester, it will only get worse,' he explains.
'We do certainly see situations where relationships between adults and their adult children do fracture and sometimes it takes a lot of work, if it's possible at all, to recover that.'
Financial costs on parents aren't the only problem, with parents also having to adjust to their children bringing home new sexual partners, with younger people increasingly hooking up via dating apps.
'In this situation, it's important for parents to be clear what their expectations are but also exercise a bit of understanding that their children are of a different generation,' Mr Tebbey tells me.
Ms Pedersen-McKinnon advises parents to charge board at half the market rent for their suburb to cover the bills and also help their children save for a mortgage deposit.
'Use it as a financial discipline practice but still give your child that extra capacity to then save the excess,' she says.
'Even the exercise of paying board, if that transaction is official, will form an important part of proving to a bank that they're a good risk for a loan.'
Those feeling generous could also potentially return that board money to their children when they qualify for a loan to help them with the mortgage repayments.
'You could then squirrel away the half they are paying to you and you could actually give that to them as a surprise bonus - nothing is expected, they have to strive hard; they're earning it, they're valuing it; they’re not taking anything for granted,' she says.
House-rich but cash-poor baby boomer and older Gen X parents are now the ones being financially strained, having to pay extra for groceries and the electricity bills during a cost-of-living crisis.
Parents with adult children at home are now typically paying $3,314 more a year on groceries for every son or daughter still living at home.
That's based on consumer group Choice's finding of 14 common items - like milk, bread, sugar, pasta, tea bags, fruit and vegetables - costing $63.74 a week based on the average shop at Coles, Woolworths and Aldi.
Electricity bills also cost $646 more a year based on Canstar calculating an individual costing $161.50 a quarter by using more appliances.
Water bills also cost $179 per person every quarter, on average, adding up to $716 a year.
Apart from contributing to the costs by paying board, adult children living at home could make things worse if they don't do some of the household chores, like vacuuming, doing the dishes or cleaning the bathroom.
'It can lead to different expectations or different understandings of what's acceptable,' Mr Tebbey adds.