The physical nature of human beings: a single penis fits into a single vagina, and that's how babies are made. It takes exactly two people for this to work. Sex can be done in other ways but this is the magic formula for sex to make a baby, and making babies seems to be the primary purpose of sex within nature. And my name isn't meant to be tasteful, it's meant to be honest. I committed the crime of public indecency and am a sex offender for life.