60+ years old?
That be my guess. And was more pissed at the noise/fun than the naked.
I've got that situation in my strata. One of the few places in the complex that kids can ride their bikes/scooters, kick a ball, etc. is a paved fire lane in front of one of the buildings. As the days get nicer and longer at this time of year, the complaints will start rolling in about noise from kids playing and having fun out there. Yeah, if kids are having a screaming match outside someone's window, that's not cool, but if they're just laughing and having a good time, how grumpy do you have to be for that to be a problem?