Early on down the journey that is raising children, MadDad and I decided that we wanted to call the boys sexual organs by the correct names, so penis, testicles, Scrotum, it is. Along the years Willie has nipped in too, but we don;t have pet names for them. Partly this was down to my experience growing up. My vagina was called a "frou frou" and my brothers penis was his tail. For a long time I thought that boys had tails to help them balance like animals and I don't remember when I learned that they urinated out of them, but I do remember the shock at finding that out.