Looking for a fanatasy story I remember

The story was set in a world where everyone has levels and classes like an RPG setting, but in a modern setting. The main character starts as a middle aged male office worker ( married with a couple of teenaged children ) with no fancy class who then gets a class as a Sucubus or some other sexualized class that transforms them to a women and has a bunch of (superficially) negative attributes which they learn to take advantage of.
Anyone recognize the story?