I'm addicted to sex with my son who isn't related to me by blood. (Shiramine Miu ADN-622)

When I was little, my mother passed away due to illness. I have a vague recollection of her face, but it's not very clear. My father ran a company and lived a wealthy life, but he was rarely home, which made me feel lonely. About six months ago, my father brought Kumi with him. She resembles my mother somewhat, but she's not my real mother. Kumi cares for me like a real son, but her gentleness makes me uncomfortable. I don't know why, but only recently did I realize that I've started to develop romantic feelings for Kumi.