When I lived in Chatswood, back in the late 80's, we had a houshold full of weekend junkies next door (they only used on the weekend & payday, which is traditionally every thursday in Oz). Well anyway next door to them, on the other side of them from our house, was a house full of art students, & every thurday & Saturday evening arround about 7PM, one of the girls there would sit naked in front of the mirror next to her window & play her trumpet (I mean that literally), then she would dance in front of the mirror then masturbate.
She followed this routine like clockwork, so everyone in our house would pile into the house full of weekend junkies with a case of beer every thursday & saturday evening & we would then have the lights off & we would sit arround watching through the window, which lined up perfectly with the window that the girl the next house down would dance in front of.
Because we would have the lights off, she would assume the house next door was empty, while we would sit arround knocking back 'twistops' & getting smashed while we & watch this arts student girl her play her trumpet, dance & masturbate naked in front of the mirror.
After about 3 months this routine just stopped, well that was after 3 months of us knowing about her routine, she stopped. I don't know whether she discovered what was happening next door.
god, we use to laugh like crazy, even though we had to be careful not to laugh too loud.