Parents who don't trust their kids (age 18 / 19) or feel anxious about them leaving home to go to Uni and don't think they can manage away from the family agree to send thier children on a holiday to ibiza (the week I saw it) with a couple of friends.
Unknown to the teens they are tracked, recorded and filmed throughout the hol, with the parents watching. Sometimes the parents hide in the VIP lounge in a club, or in the storecupbaord of the tattoo parlour while dd gets a tattoo. They watch them snogging in clubs, even get into the hotel room and pick thorugh their stuff.
Then on the last day, da DAAA, they are revealed and spend the last night on the hol with their kids and the friends. In Ibiza the reveal took place in a lapdancing club. ("That's my boy" said the father).
Then the parents chuckle about their drinken exploits and admit that they were wrong and the kids are just like they were and quite responsible. In the Mum and her cousin's case, the mother was equally keen to go clubbing and get bladdered on vodka as her tattooed dd.
For a bit of extra voyeuristic interest they take the parents off for a day to do something cultural - wine tasting, which one couple appreciate in a thoroughly naice way and the other makes faces, looks bored and dream wisfully of a Long Slow Screw up Aganst the Wall. The cousin in this outfit was notably too ill to film on the last day.