A documentary starts up, and it's one about hermaphroditism. You've covered this a little in biology before- hermaphrodites are animals that have both masculine and feminine reproductive organs. It shows a few examples you've covered- earthworms, toads, clownfish- but you notice something weird. The narration is turning you on. You blush as you realize you have an erection.
"But of course", the documentary continues, "the closest animal to human analog to human reproduction is the flatworm. Like humans, flaworms are both male a female at birth, capable of impregnating and being impregnated. When two flatworms mate, a sort of jousting match occurs, with the both flatworms attempting to impregnate the other. The loser carries the winner's children, but and then has a chance to try the ritual again the next mating season." As you continue watching, you can feel your body shifting. Small breasts form on your chest; no larger than an A cup. You feel your skin becoming softer as your face changes into a more androgynous shape, and your erection has been joined by a warm feeling *below* your penis that you somehow innately know is your new vagina.
The documentary continues: "In humans however, the change is permanent. Once a human has been impregnated, their penis will detach, and their body will become drastically more feminine."
Mrs. Gray returns and stops the documentary. "I show this to you, class, as a warning. As high school seniors who have reached 18 years of age, all of you are likely to become sexually active, if you haven't already. Make sure that you use protection unless you're ready to deal with the permanent consequences of getting pregnant. Accidental feminization effects thousands of men in this country each year. Don't be one of them.
The bell rings and class is dismissed.