What's interesting to me is that movie is seemingly trying to make a statement about how much "secrecy" and censorship surrounds female genitalia, this is most evident in the Sex Ed scene. Yet in this movie what does it NOT show? And what does it show a lot of?
To be fair, showing a vagina with teeth would bump the movie into Troma territory. It would just look ridiculous. And why does the movie not showing what it's saying is surrounded by secrecy suggest hypocrisy to you? Why not interpret it as one more way to reinforce its theme?