This was absolutely fascinating! I enjoyed every word. It was written perfectly. I love the characterization. It was so twisted and wrong, yet completely .. (oh clichés you never fail me) right. Certainly believable. Of course their relationship couldn't be anything close to normal.
I loved how it started as a "game" of sorts and just evolved rapidly in riddles into..well. So perfect. (omg this sentence doesn't make sense but I'm keeping it in here anyway! Sorry!)