Like the "sex talk" neither parents nor children enjoy, discussing money and especially money after death (inheritance) is something keenly avoided by many.
However, the unwillingness to discuss whether parents intend to - or are able to - leave an inheritance for their offspring means there is increasingly an expectations gap.
Last week an Australian survey suggested parents were considered "stingy" by their children, for "racing around like oligarchs and burning through their bank balances" instead of preserving assets to help their kids into a new home.
National Seniors Australia and Challenger quizzed 5800 Australians aged 50-plus and found only three per cent plan to preserve their savings to give to their kids after they've gone.
Just one in four of the respondents said leaving behind a family nest egg was a top priority.
Unfortunately a reasonably large percentage of millennials (the offspring of the over 50s baby boomers) hope, nay expect, their parents will share some of the assets they've been able to accumulate by living in an era of house price inflation.
Rather than being stingy, a substantial proportion of the parents surveyed said while they hoped to leave their children some money, their biggest priority was funding essential needs in retirement and making sure their money lasted.
In the UK, research from SunLife also showed an expectations gap. One in five adults rely on getting an inheritance, hoping for an average £147,000 windfall to get them out of money trouble.
However, family members will actually be bequeathed around £119,000, and if historic trends are an indication, will 'blow' more than £21,000 of it on holidays, home improvements and big ticket items rather than clearing debts.
As for the heirs of American baby boomers, a survey by investment firm US Trust revealed just 49 percent of millionaire boomer parents considered leaving money to their kids a priority.
One-fifth of respondents fear their children would squander an inheritance, and one quarter thought it could make their heirs lazy. These parents suggested after decades of personal and professional sacrifices for their children, and after paying for education and helping with first home deposits, enough was enough.
Survey results and anecdotes from financial advisers around the world point to common themes.
There are often unrealistic expectations with people expecting to receive far more than they actually do; confusion arises from a lack of communication; and discussion around money and inheritances can lead to (or add to) family drama.
The surveys illustrate the depth of feeling -with many potential inheritors suggesting seniors have had it relatively easy and should share their good fortune with the current generation.
Then there are the boomers who think millennials are greedy and entitled: "We worked hard to make our money. You should do the same, and not rely on the Bank of Mum and Dad".
I have seen instances of older parents going without, in order to leave something for children who don't expect anything, and are better off than their parents already.
I've also seen kids' inheritance expectations dashed as the parents lived long lives and spent rather more than the kids thought (or hoped).
Best laid plans can go awry, with large market movements or unexpected health costs shrinking the nest eggs of many a retiree.
While every family's circumstances will differ, and there is no one-size-fits-all solution, communication is an easy and important first step.
While your kids can learn about the birds and the bees elsewhere, they need you to tell them about the family finances.