My parents got divorced when I was 12 and my Dad moved out. I lived with my Mom until I left for college but spent most summers at my Dad's house. My Dad had several girlfriends over the next few years and I fantasized about all of them, but I never thought anything would actually happen....
He married Denise when I was 16 and they bought a new house together. I came to stay for the summer about 4 or 5 months after they got married. My Dad lived in a different city than my mom and I really resented staying with him as I had no friends around and since I had little to do I just hung around the house a lot. Denise was 34, short and skinny with nice tits. She had short brown hair and looked like she was in her late 20's. I probably jacked off to her at least twice a day at that point.
My Dad worked long hours and Denise and I were alone frequently as she had gone back to college and was only working part time. I think that Denise was trying to make sure that we got along well and would act like a buddy, certainly not at all like a mother figure. One day as I was eating breakfast she walked up behind me and rubbed my shoulders for a few minutes. I told her that it felt really good and she offered to give me a "real" massage. I of course jumped at the opportunity. She told me to take off my shirt and lay down on the floor in the living room. She then proceeded to give me a pretty decent back massage but it was not at all sensual or erotic. This scenario repeated itself almost every day for a week and then one day she asked me to rub her back. We then started exchanging rubs each day after my Dad left for work. She normally wore a bath robe around the house and during her rubs. I started pretty professionally, keeping my hands on her back or legs without getting near her crotch but each day I got a little braver and would inch my hands a little higher. I'm sure she knew this but she never protested. It got to the point that my hand would lightly rub her panties. I never got brave enough to just move my hand to her pussy.
One day as Denise was giving me a massage she straddled my back and sat on me, which she had never done before. I could feel the heat coming from her crotch on my back and I was very hard. After a few minutes of this she asked out of the blue if I was a virgin. I told her the truth (Yes) and then she told me about a co-worker of hers that had given her son a "Guided Tour" I laughed nervously and asked Denise to see if her friend would give me a guided tour. She asked if I would like one from her. I immediately pushed up from the ground and Denise scooted back and I as I turned around I could clearly see her panties. She told me that nothing was going to happen but she thought I could use some guidance.
I sat up and just watched as she pulled her robe open, pulled her plain white cotton panties off and then brought her knees up and spread her legs. She then proceeded to spread her labia and point out all the parts of her vagina and explain. She gave me a little guidance on how to touch a woman and how to rub a clit, showing me by rubbing hers. I asked her about how to go down on a woman and she gave me a little description of how she liked to be eaten like an ice cream cone. I started to move my head toward her pussy to give this a try and she pushed me back and repeated that nothing was going to happen.
I asked her if the clit was the same thing as the G Spot. She said no and explained that the G Spot is on the inside and she couldn't show me. I asked her how to find it and she took a moment and kind of sighed. Then she asked me if my hands were clean and guided my hand to her pussy. I slid my finger into her pussy and she had me push down on her abdomen with the other hand. She gave me a little direction and told me when I hit the G Spot. I rubbed it for a few minutes and then she asked me to rub her clit with my other hand. I did this for a minute and realized I should just go for it. I moved my head in again and this time she didn't push me away. I began licking her clit like an ice cream cone while fingering her G Spot. She came hard after a few minutes and then looked me in the eyes and asked me to fuck her. I nearly came in my shorts just from hearing her ask me to fuck her. I pulled off my clothes and climbed on top of her. She took my cock and guided it into her pussy. It was so hot and wet it was incredible. I took probably two strokes and shot my load, but I stayed hard enough to keep pumping. I kept at it and after about ten minutes I came again. I'm pretty sure she had come again as well. I pulled my cock out and she got up and started to walk to the bathroom for a shower. She turned around and asked me if I wanted to get in with her.
The shower was great. She laughed at me as I ran my hands all over her body and played with her tits for probably ten minutes. After a few more minutes she got on her knees and took my cock in her mouth. She gave me a fantastic blow job pumping the base of my cock as she twirled her tongue around the head. As I started to cum she sucked really hard and I felt like my balls were going to somehow get sucked through my cock, I could not take the sensation, it was too intense. I shot my load into her mouth and she smiled and swallowed.
We probably fucked every day for the rest of the summer. I was seriously considering moving in with my dad for good but Denise told me that she was feeling guilty and would have to stop fucking me. We had one last fling before I moved back to my Mom's house and we fucked for hours. We hit every position at least twice and finished in a furious 69.
My Dad is still married to Denise but she and I have really never spoken about it since then. We just kind of pretend it never happened.