There's a dirty little secret about family travel. And it's got nothing to do with poo exploding from a toddler's nappy in the back seat of the car. (Seven years ago in Coffs Harbour; we still bear the scars.)
About one-third (35 per cent) of Australian travellers have been on holiday with more than one generation of their family in the past two years, according to new research from Expedia.
But many of us aren't doing it out of the goodness of our hearts: "Oh, poor grandad hasn't been well. Let's take him on a lovely trip to the country!"
Get this: four in 10 parents (38 per cent) admit they probably wouldn't invite grandparents, aunties or uncles if it wasn't for the free babysitting.
These travelling UFABS – Using Family As Babysitters – are shameless.
"Nan, the kids miss you so much. How about a week in Noosa? You can have time with them, while we make ourselves scarce. Don't worry, we won't get in your way!"
Others are subtle: "Aunty Phil, you need a break. Let's all go to Bali!" Then comes the bait-and-switch. "Oh dear, I'm a little worried about the quality of the babysitters here. You hear terrible stories! Would you mind looking after Jeremy while we pop out for dinner tonight?"
To make matters worse, 45 per cent of travellers agree to these trips being funded by the "older generation". That's right: The slave labourers have to pay their own way and fund their masters. (Quick, someone call the union.)
Now, most grandparents adore their progeny. But expecting them to work on holidays is exploitation.
Perhaps there should be parameters? Say, one or two nights of babysitting per week away. And parents pay their own way.
(Include a moratorium on complaining about the mother-in-law or father-in-law for the term of the trip.)
Now multi-generational trips are mainstream, there need to be ground rules.
But not all of us are UFABS. Jenny Douneen, Sponsorship and Integration Director at Carat Australia, is a single mum who went to Fiji last year with her three kids, parents, and siblings' families.
"My parents hosted this trip and it's something that we do as a family every now and then," Douneen says. "We then supported additional components and covered our own expenses."
She regularly takes the kids on weekends to Canberra with her parents – and not just for the babysitting: "More so the kids can spend some quality family time with their grandparents."
Four out of five (80 per cent) of parents say the additional help makes their holiday more relaxing.
Which begs the question: what about the other 20 per cent?
Probably sitting by the pool, in a fug of guilt, over granny-grappling with the toddler. Or worried that someone will find out their dirty little secret.