My kids have reached the age where it's often easier to have friends over, because at least then they're amused by their peers, rather than whaling on each other and/or asking me--of all the incompetent people--to entertain them (see prior post titled "Bad With Kids.").
But these play dates create a different dilemma. The scenario unfolds the same way every time. All the kids scurry off into a room out of the line of sight and mostly out of earshot. An erie silence descends on the premises that can mean only one of two things: (1) they are playing nicely or (2) they are up to SERIOUS mischief and mayhem.
An inner debate follows: do I peek in on them or not? If they are playing nicely and catch me looking, disruption will break the spell and result in requests for messy, multi-step snacks (e.g. smoothies), cartoons, "experiments" with spices and food coloring, or similar undesirables. However, if they are painting the walls or pulling every feather out of the pillows one by one or worse--doing something truly dangerous like sticking their heads in a plastic bag or playing "tractor accident" or something--then intervention is called for, especially since I am supposed to be supervising someone else's kids.
I usually creep up to the door in an attempt to ascertain whether we are at war or peace, and can't always tell. I'm not sure what the solution to this dilemma is. It's like some sort of parental riddle of the Sphinx, better left unanswered.