Watched In The Shower

Years ago, I lived for two summers at my girlfriend's house, while we were home from college. Her mother was divorced and lived alone and was incredibly nice to me, and I tried to take care of things around her home to help when I would stay there. I am still married to her daughter, and I have never admitted this to her or would never want to rock the boat since we have a great marriage. This is the first time I'm telling this to anyone. When I would stay at my now mother in laws house, I would have to get up super early each day to go to work, I worked for a roofing company. I had a routine and each morning I would get up, use the restroom, go down to the kitchen and eat a quick breakfast, return to the bathroom and take a shower and get dressed for work. It was still dark when I would get up and the house was quiet with everyone else there still asleep; it was just my future mother-in-law, and my future wife there. One morning I noticed that the pocket sliding door in the bathroom wasn't completely slid shut and so I shut it before getting into the shower so that the light didn't wake up my mother-in-law, as her bedroom shared that bathroom. I noticed the next day that the door was slightly open again when I walked in and shut it and headed down to make breakfast. When I was back in the shower, I noticed that the door was slightly cracked open a couple inches again? I filed that away in my mind and went on my way. The next time it happened again, I knew it had to be on purpose. I didn't shut it anymore and stood at the sink shaving and looked at the door in the mirror's reflection. My mother in laws bed had a very clear view into the bathroom and I could see her in her bed "sleeping". I also realized that she could see into the shower through the sliding glass door from her bed and her room with the door slightly open too. The thought of being watched as I showered really turned me on, and as I grew hard, I had to stroke myself. The hornier I got thinking of her watching me the more I stroked until I was spraying cum on the glass shower door. This went on for the remainder of the summer, and the next as well. It also progressed to the point that over one Christmas break that I was staying there, I would get up a little later and she would be downstairs in the kitchen, After I ate breakfast I would head upstairs to shower and get dressed, she would too nearly right behind me, and often by the time I finished shaving, I could see her through the slightly open door, sometimes totally nude changing into her workout clothes, or on occasion when it was still really early, masturbating in her bed as I was showering, I still get hard thinking about letting her watch me stroke myself to orgasm and spraying jets of cum on the shower door for her as she watched. It's been many years since, and neither I or her have ever mentioned anything at all about this to each other or anyone else. I do wonder if she ever thinks about watching me after all this time and my mind races to that experience each time, she is around me still.