Grandma's Lessons

Long story short, I Jeff 20 and live with my parents 2 siblings and grandma on our farm. I've always been shy around strangers and when my parents went away for a week with my 2 younger siblings. I was left to take care of the farm and grandma Rachel 59 would cook the meals. I wasn't a good student and left school at 15 and worked full time on the farm. I didn't go out much and played games on my computer and watched porn as well. Rachel had lived with since Alan died 4 years ago. The second night my parents were gone I was in my room masturbating watching porn on my computer, Rachel was watching TV her favorite show was on that night. But due to some problems at the TV station it wasn't on and so she came to see me about playing cards. She walked in and caught me cock in hand and porn on my computer. She said I was going to ask you to play cards, but see you have your hands full. Turning around and leaving the room. I turn off my computer and put my cock away and went to apologize to her. She told I didn't need too and said I should finish what I had started. But I answered it was all that important, nonsense she responded and told me to go and finish. I wasn't really keen to start again as I was still a little shocked at get caught. Rachel then offered to help me get myself off as she called it. I still didn't move and she said lets get naked on my bed and I'll help you. She lead me to her bed and she got undressed and started to undress me as well. I laid on my back and she started stroking my cock. It was soon rock hard and then she started to suck my cock and I came in her mouth. I hadn't warned her and it didn't seem worry her. She got me to play with her body and showed how to go down on her, I soon had another hard-on and she got me to mount her. I stayed the whole night with her and the next day after I had done the chores and was sitting watching her, she asked did I want more lessons. Yes please I answered and we went back to her bed and fucked again. That was how it was until my parents got home, I was worried I wouldn't get anymore sex from Rachel for a while. But Rachel made sure we got together regularly and fucked.