When Did That Happen Parts 2

Part 3
Mary called me before I got home and she seemed to understand why I had left. I was back in my motor home by afternoon. Throughout the drive my troubled thoughts had kept me going but as the AC removed the heat from my home I lay down and dropped into a deep restful sleep. I awoke about sundown. At first I thought it was morning but then I realized the sun was coming from the wrong direction. I prepared a light meal and as I ate I determined that I had to straighten out my thinking before my dear one’s return. She was due back in three days.
I sat down at my computer with the intent to begin at the beginning. What follows is that beginning.
Our parents had gone back east to a funeral leaving 17-year-old Mary and seven-year-old me alone. We were living in an unfinished home without plumbing. It was in the great depression remember. Mary was a clean freak wanting us to bathe every other day. It did not matter that to take a bath a thirty gallon wash tub was placed in the middle of the kitchen and water carried from the spring was heated on the stove. When she finished her bath she would add a bucket of hot water to her cooling bath water and call me in to take my bath.
This day, instead of going to my room to read I had spied on her. I watched her undress. I don’t think I was seeing anything I had not seen before but the sight gave me a boner. I had begun getting boners often and I had discovered that it felt good when I played with it. So, I pulled it out and stroked it while I watched. When she finished rinsing off she stood in the tub and dried off. When she had dried all except her legs she placed one foot on a nearby chair. In doing so, she opened her sweet young pussy to my view. Now this was something I had never seen before.
I remembered back to a few months earlier a neighbor boy who was a year or so older had talked me out of a candy bar by promising me he would let me see his twin sister’s pussy. She had refused to let me see but of course by that time I had given up my candy bar. Well, here I was seeing my sister’s and I was sure it was better than seeing a little girls.
Mary put on her white terrycloth robe and poured a bucket of hot water into the tub. I stepped back and put my dick in my pants. She called, “Em, it’s time to take your bath.” I waited a moment and then walked into the kitchen. She was seated at the table running a brush through her hair. “Better hurry before it gets cold.” She always said the same thing. I undressed and stepped into the tub. Just as I began to squat down I heard her say, “Oh my.”
I looked at her and saw she was looking straight at my hard-on.