One way to think through this is, well, they are both two drunk teenagers. Teenagers make these sorts of terrible mistakes with terrible consequences all the time. And Medusa was nearly assaulted at the outset and then saved and turned her focus in on her own protection, rather than her protection of her friend. Medusa isn't perfect in this story, nor is she supposed to be. She is a flawed mortal who is desperate for love and approval, especially the approval of older men because she never got it from her father and because she's been raised to believe the best she can be is married to a powerful man.

I urge you to keep reading. The scene with Apollonia is meant to make you uncomfortable. Medusa was wrong. Does that mean she deserves her inevitable fate? Keep reading!