I'm at a friend's house and her 5yo dd and my 7yo ds are playing together happily and quiety upstairs. I've been up and they're playing mummies and daddies but so far, fairly innocently (I overheard 'you've got the Porsche, I've got the Ferrari, wtf? I have a Focus!). In the past they've played looking at each other's bums and we've told them they mustn't. I've just reiterated that bums are private. Would you leave them to it or insist they play within our sight? Friend just went up and they jumped when she walked in, help! TIA.