When Melinda Gates found that time and time again she was the last one in the kitchen after dinner, finishing off the clearing up, she didn't simply wring her hands in frustration, she laid down the law: "Nobody leaves the kitchen until mom leaves the kitchen." And that was that.
Sure, it wasn't immediately popular with her billionaire husband and three children ("they certainly remember that particular transition," she says, roaring with laughter) but Gates was adamant that she was not going to pick up more of the slack when it came to household chores simply because she was "mom".
It's this kind of no-nonsense approach to the division of labour in her own home - which she shares with her children Jennifer, Phoebe and Rory and her husband, Microsoft founder Bill Gates - that is at the heart of a letter released last week by the couple in which Melinda calls for the burden of unpaid work that falls disproportionately on women to be redressed globally.
She is, after all, one half of a couple which, aside from being the richest in the world, has put billions of dollars in the past 16 years into changing the lives of disadvantaged people through the Bill and Melinda Gates Foundation. So when Melinda speaks; many listen.
There is a gap, she says, between the amount of time that women put into unpaid work compared to men. "Whether you're in a western country where that gap can be 90 minutes or in the developing world where there can be a five hour gap, if we don't talk about how it robs women of their potential, then we're not really looking at the issue," she tells me animatedly on the phone.
"And if we don't redistribute the work, if we don't really say: 'there needs to be a different balance here', we're not going to get all the way. We're not going to let all women reach their potential all around the world or get the big GDP gains that we want."
For Gates, whose half of the letter is titled 'More Time', a nod to the fact that women in developed countries continue to take on moredaily unpaid work than men - which is totally unacknowledged. She believes this is a huge problem which has serious knock on effects on society and the economy.
"If we can add 10 trillion dollars to the GDP by looking at the unpaid work that happens at home and really calling it what it is - work - to me it doesn't make any sense that we're sitting in 2016 and we're not labelling it like this.
"Why don't we call it work and then why don't we recognise the women who are predominantly doing it?" she asks, her frustration evident.
It is, she says, not just an issue for policy makers - though she has been encouraged to see topics such as paid family medical leave crop up on "both sides of the aisle" during the US presidential campaign - but rather something which starts in the home.
So does Bill pull his weight and do his fair share of household chores? "He's not much of a cook but he's really good at doing dishes," she reveals (Bill admits in the letter that he can do "tomato soup" but not much else). And he does the school run too, inadvertently encouraging other dads at his daughter's school to follow suit after the mums went home to their husbands and said: "if Bill Gates can drive his daughter to school, so can you".
But as well as unpaid labour in the home being an issue for couples to discuss openly - Gates is adamant that real change only happens when we address our children's expectations of their roles in society. That's why this joint Bill and Melinda Gates open letter is addressed not to the journalists and politicians looking to see what the world's richest couple will turn their attentions to next, but rather to America's school children and, one imagines, her own. "Even in US households today boys are 15 per cent more likely to be paid for their chores," she says, "and they're more likely to be assigned outdoor chores. This absolutely affects everyone and that is why we need to talk to boys and girls about this.
"You have to change boys and girls' expectations when they're young so that they then take those issues up as they get older and start their own careers and start to have a family."
Women working at home- schwabepharma.co.uk
The last line reads like a direct message to her kids: "I can't wait to see where your steps will lead you. Not necessarily in triangles. Not in straight lines, unless that's what you want. But in any direction you choose." Did she write with them in mind? "I'm writing it to my daughters, to their friends, and to my son and to his friends," she says. "I imagine a future for them that is even different from the one I've had. And I've been incredibly lucky, so lucky as a woman. And yet we're not far enough in the United States.
"I know from listening to my kids and their friends-and from looking at polling data about how teenagers see the future-that most girls don't think they will be stuck with the same rules that kept their grandmothers in the home. And most boys agree with them.
"I'm sorry to say this, but if you think that, you're wrong. Unless things change, girls today will spend hundreds of thousands more hours than boys doing unpaid work simply because society assumes it's their responsibility."
So how do we do make this happen? According to Gates, we have to "recognise the problem, reduce it and redistribute it". She has pledged to lead the charge by exposing these iniquities ("women in developing countries are spending 100 million hours a day just carrying water") and taking steps to change them in the coming months - one of the foundation's primary goals is to ensure women have access to banking services wherever they are in the world. "If they don't, that leaves them completely out of the economy," she tells me.
In our telephone conversation, Gates won't be drawn on who she is rooting for in the US presidential race - a wall seems to come up when I ask her about it - but Hillary would be a pretty safe bet. The Clinton Foundation and the Gates foundation have been collaborating on a project called 'No Ceilings', which gathers and studies data on the progress of women and girls around the world. Gates shared a platform with Clinton and her daughter Chelsea on International Women's Day last year to launch the project (which was funded by the Gates Foundation) and lay out key goals to help gain equal rights and participation in all levels of society for women.
It's evident that the two women think alike. "I think Hillary is talking about lots of issues in the campaign which is great," she says in a measured tone. "She always has, her entire career, talked about things that affect women and girls."
But Gates is confident that women's issues will continue to be debated after this presidential campaign. "I think there's a good chance there will be some policy change in the United States after this election," she says. "And I think it's going to happen no matter what. Women are starting to demand it."
By Eleanor Steafel-Telegraph UK