Too Young Not to

I am pretty new here and this is one of my first attempts to share a past experience. I was 16 years old and experiencing a hot summer with my girl friend Jenny (I have not shared this with anyone). We had begun to date during 9th grade and by August there wasn't much we hadn't shared. One night my parents were out and Jenny came over to watch tv. We were downstairs and soon we were making out and exploring each other's body. It didn't take long and we were naked and making the most of our time together. Our previous sex had involved only missionary style and had been wonderful but we had discussed doing it doggy style, little did we know? We decided to try it doggy style and Jenny got on the couch with her knees on the floor and I got behind her and entered her. I grabbed her hips and began to pump in and out of her pussy. It felt so good and Jenny was enjoying it too, I 'm not sure how long we fucked but we were both making noise and loving it. After I came I pulled out and sat on the floor. Jenny stayed bent over the couch and didn't move. My yellow lab, Cody, had been sleeping in the chair across the room, all of a sudden he got up and came over and sniffed Jenny's ass and cunt and then licked her. Jenny didn't move or say anything, then Cody raised up on the couch on his two front legs and began to try to fuck Jenny. Jenny still didn't say anything. Cody was having difficulty finding the right hole so I reached over and grabbed his dick and put it inside Jenny's cunt. Cody couldn't get enough of Jenny and just kept fucking her and fucking her. Jenny never said a word. Finally he finished, pulled out and went back across the room and laid down and then began licking his dick. Jenny finally moved off the couch and sat down beside me. Then she said I could feel him squirting in me every time he polked me. Neither of us said anything more about Cody and after awhile I walked Jenny home. Summer moved quickly that year and soon we were back in school enjoying 10th grade. Jenny and I never spoke of that night and continued our relationship as if it never happened. Two months after school started Jenny moved to Chicago with her parents and I never saw her again. Although several months later I heard she had a litter of pups.......