Since my sister and her son Matt moved into my house

Since my sister and her son Matt moved into my house four years ago, I have taken complete control over him. My sister has had drug problems for many years and by the time they moved in he was an arrogant brat. After a few months of his misbehavior and fresh mouth I told my sister that I would take over disiplining him and if she didn't like it she could move. I was divorced and only my daughter Paula lived with me. Matt was nine the first time I actually spanked him. He couldn't beleive it when I pulled down both his pants and underwareto do it. I realized then that the embarrassment was more punishment than spanking itself. He constantly got in trouble at school and at home and the spanking and grounding seemed to have little effect on his behavior. By the time he was ten I was very frustrated with him and his mother seemed not to care. One day I was so mad at him when he got home from school I first scolded than told him he would get spanked. He actually smiled at me which made me more furious. We were in my living room and my daughter Paula was there also, she was 17 at the time. I was so mad I just told him to undress right then and there. The smile soon left his face since I never spanked him in front of Paula before and he started to cry before I even touched him. I told him if he didn't undress I would do it and he reluctantly starte to undress. I made him take everything off including his shoes and socks. When he was finally naked I made him bend over the back of a chair and I spanked him with his own belt. He cried like a infant and I know the humiliation of Paula witnessing it made it more degrading for him. When I was done spanking him his rear was completly red and I made him stand in the corner for half an hour naked. Over the next year or so he started to behave better and I know he was very afraid of me. I treated him like a six year old and when he was in trouble and grounded I would even bathe him or have Paula bathe him just to humiliate him and give him no comfort while being punished. He is almost 13 now and I still punish him the same way even though he is much better behaved now. The last time I spanked him was a month ago and I grounded him for a week. When I spanked him I made him strip naked as usual and again Pauls was there. He is starting to develop and has some pubic hair and I know he is more embarrassed than ever. The whole week he was grounded I bathed him every night except Thursday when I had Paula bathe him. He was so embarrassed he cried the whole time I washed him and Paula said he did the same when she did. I even noticed a couple time when he was in the bathtub he had an erection. I didn't say anything abot it but I'm sure he was totally humiliated. I know he fears me and I told him I can make him even more uncomfortable if he doesn't behave and do well in school. The fact that Paula and I see him naked and even his mother sometimes has changed his attitude. He is more respectful and has done much better in his school marks. Recentlly, most of the time all I have to do is threaten him with an enema. The only time I ever did that to him was last year. I made him lay over my lap naked in the bathroom. Paula was in the room also and afterwards we stood and watched as he sat on the toilet. That was the most degrading thing I ever did to him and he remembers it well and is petrified if I even say the word enema. He is not at all comfortable around me and tries to stay out of my way. There is a noted improvement over him now and the way he was 4 years ago. I know he must hate me but I really don't care as long as he turns out better then his mother.