I had moved in with My Sister in Law Mary,just over two years ago. We had both been married but lost our partners. She had been left a big four bedroom house. It made sense at the time when she asked me to move in with her. I had my own small lounge and bedroom. All the upstairs rooms had locks on the doors not sure why but came in handy for hiding my fem wardrobe. I had never had any sexual desires for Mary she was 56, a size 10 but always dressed frumpy . Trousers big jumpers and from looking in the washing basket nothing to excite me undie wise. We hardly noticed each other and spent little time together. I was sat on my bed looking at myself in the mirror thinking how I had let this happen and how stupid I looked when she walked in through the open door. She stood silent looking at me. My head slightly bowed I thought she looked different , she had not changed and was still in her black business suit comprising of a pencil skirt just above the knee, Jacket and underneath a white shirt style blouse. I noticed she had heels on around 4" . Makeup and her hair loosely tied in a ribbon not the usual frumpy bun style and certainly not what I had seen before. What happened next totally surprised and shocked me . She almost ran at me slapping me furiously with her hands. I had never hit a woman and was not about to now. I was holding my arms against my face . I knew I could overpower her but just accepted her . I fell off the bed on to the floor she landed on top of me worming her way up My silky clad body till she had my shoulders pinned with her knees. She was breathing heavily her hair loose now over her shoulders. Her skirt had ridden up her legs. She was wearing Stockings, I could see the tops of her stockings but not her knickers. I could feel my clitty cock hard against my panties. I wanted Mary right now. She had seen my facial expression and probably read my lustful thoughts. Her hand smacked my cheek hard. It stung but I was still rock hard. She said "you dirty little pervert I have a good mind to tell your friends and mine what a sissy pathetic man you are. I said please Mary no. She said "shut up speak only when I tell you to" I had never seen this side of her before. I had lost my erection now. The realisation of what she had said sinking in . She said "I am not having you living in this house not knowing if you are dressing behind my back' If you want to stay you will dress all the time in your slutty underwear. You will wear a dress or skirt and blouse in the house and a nightie for bed. If you have to go out , only with my permission. You will wear your full underwear under your male attire. You will do whatever I tell you or face the consequences". My mind was in a turmoil I could see no way out . I had to do what she said. She was still pinning me to the ground with her knees. She said "well what is it to be". I nodded and she slapped my face again. " I asked you a question answer me now" I said yes Mary I will do as you ask please don't tell anyone She got off me, straightened her skirt and left me lying on the floor. I lay there for some time confused and berating myself for letting this happen. I knew I had no control of my crossdressing desires having tried many times in the past to stop and throwing my gear away. I thought maybe this is what I always wanted to dress fully all the time. Maybe it wont be so bad after all???