This Sinful Virtue

What if a world existed where the morals, truths, and ideals that we have been taught all our lives were turned on their heads? Where things that we believe are sinful, wrong, and horrible are not only accepted, but revered? This is the reality of Helvetti, the world of twisted evil. There are seven main countries, and these countries represent what we know as the seven deadly sins. Every few years, the most evil, demented, and twisted children from each of these countries are sent to an elite school on the island of Paaralan. This year, a Greedian named Avaritia Mania Mammon was chosen. Known for being manipulative and always getting what she wants, she seems like the perfect candidate. At the school, she makes friends with a Wrathian boy named Abaddon Mictian Dagon, a demented sadist with a love of blood.
Eventally they start feeling attracted to one another, so they become friends with benefits. It's normal for a girl and boy who are friends. But what happens when it goes beyond the primal, physical lust? That's right, total mother-milking mayhem.