Caught by Grandma

I'm Duncan 23 going to university and don't have a girlfriend. So, I masturbate to get off and on my last break from university. I was home alone my parents were working and I decided to get myself off. I was reading a porn mag and stroking my cock when I caught by Christine 61 widow my mother's mother. She had come over to doing her washing as her machine was not working and awaiting parts. She had her own key and so entered without knocking catching me masturbating. After an awkward silence she went and put her washing on and then returned. I waited for her to tell me off, but she offered to get me off and I was shocked, she took the lead. But she decided my bed would be better than the lounge and so we went to my room. I was told to get undressed and lay on the bed, I done as I was told. She undressed completely herself and started to play with my cock and then started to suck it. Once she was happy with its response, she mounted me and rode me until I came inside her. We fuck twice more and have continued a sexual relationship ever since. I go and visit her; she lets me fuck her most times.