Mowing Grandma's Lawn

I'm Colin 20 only son of Graham and Monica and high school dropout, my 2 older twin sisters are at university. I'm training to be a plumber and should finish the end of the year, on a trainee wage is not great. So to do whatever I want I do odd jobs to make extra cash and I got got the job from my father to mow his mother's lawn, not as much as I would get otherwise. But she's family, Kristy 64 widow of 4 years and lives alone. Graham is far too busy to visit her much at all, with work and playing golf and so he can't do the mowing himself. I don't mind as she a great cook and also I get to see you her as well. Last year I was mowing her lawn and finished it bout 2pm and I cleaned her mower and put it away and went to see Kristy and get some cake and a cold drink before leaving. A few of her neighbors were also mowing their lawns still, I got to the back sliding glass door and could see inside the house. Kristy was masturbating herself with a big rubber cock and I was shocked and horny at the same time. I was just standing there when she saw me and let out a bit of a scream. That bought me back to my senses so to speak, she also calmed down and noticed the lump in my pants. Forgetting her getting caught turned her interest to my lump and asked me to show her my cock. I did as she wanted and she couldn't stop herself from playing with it. One thing led to another and we fucked twice that afternoon. That was the start of regular sex between us and I found out my gran loves fucking. We still continue fucking regularly today, but once I had fucked her. I was hooked on mature woman and not really able to chat them up myself, but I started checking out every mature I saw. Finally I found one that I thought might left me fuck her. Monica 44 my mother, she was rarely getting sex as far as I could see from Graham and alone a lot of the time herself. So I started taking notice of her routine, especially when Graham was away or playing golf. I noticed that she retired to her bedroom to take a nap she would say if I was home. I started to look for a way to see inside the bedroom, but it was upstairs and no keyholes either. Finally I decided I should walked in and catch her masturbating, but how was the question. I needed a good excuse and I decided to injure myself slightly and walk in catch her. It wasn't unusual to be looking for band aids especially when I worked on my car. The Friday before I was was going try it, I got a cut at work. I kept hidden from everyone at home, Graham 47 went golfing and Monica done her shopping and on her return she put everything away and after dinner was going to have a nap she said and I said I was going to work on my car. She went to her room and I got a glass and put it against her door and listen. Nothing at first and just went I was going to give up, I heard a soft moaning start, I remove the covering on my work cut and got it to bleed and with a paper towel over it walked in catching Monica playing herself. She wasn't happy on getting caught, but calmed down and got me a dressing for the cut and dressed it for me. She was still naked and after she had dressed it I kissed her. She was shocked by my action at first and I continued kissing her and then started to feel her up as well. She let me continue and we final had sex for the first time and it soon became a regular thing for us to fuck and with Kristy also letting fuck her I'm in heaven as they say.