With enough work you could do a two layer wayback. I remember an article from the 1960s called the girl detector, intended for frat houses and the like. It generated a wolf whistle when presented with the appropriate gender. I think it was in the US magazine Popular Electronics, and it was a transistorized update of a much earlier vacuum tube circuit. The fundamental idea wouldn't work today. It was an infrared sensor that detected the temperature difference between someone wearing a skirt and trousers, so wouldn't be a reliable sexer today.