Mom and Dad had sex as I did Rex

Mom and Dad actually had sex one night and I overheard. Majorly turned on. I played with Rex During one of the few times, at least it felt like it, that my parents spent some quality time together. I'm sure they did more than I knew it was just a time I knew about. It was around midnight, and I was supposed to be asleep but I hardly ever did what I was supposed to. I was actually reading a Gothic romance and rex was Curled up at my door. I suddenly began to realize that I could just hear faint sounds coming from my closet. I got curious so I went to it and it got a little louder. I listened and it was strangely coming from the bottom of my closet. I still couldn't make it what I was hearing. I began to quietly move stuff at the bottom of my closet. Using my phone to search, I found nothing but a vent that I didn't know was there. I pushed the little lever on it and the sound got louder. Listening I realized that I was hearing mom. Then I heard, "your still so tight!" I was stunned, I was hearing my parents fucking. I don't know why but hearing them got me worked up. I listened for a couple minutes before I decided that I wanted to get laid. With the vent open I could hear them easily in the silence. I went to rex and I reached out for his sheathed cock and started rubbing. After a couple moments, he woke up. As he started growing i tapped my chest. I sleep in a Tee but no undies. I leaned back as he crawled on top of me after sniffing me. I was very wet and he moved between my legs and made a few attempts before his growing cock found home. I bit my lip to keep from being loud as I heard my mom being very vocal. Rex was deep inside me and I heard my dad grunt that he was cumming. I heard mom tell dad that she wasn't through yet. Neither I nor Rex was either. I heard dad tell mom to suck his dick. Rex was fucking me very fast. Almost like constant. Hearing mom slurping dad and hearing Rex fucking my very wet puss was such a turn on. I was so close when I felt Rex's knot start growing. I came knowing that I was getting exactly what I want. Feeling him grow right on my spot had me cumming several times. That's when I heard mom tell dad to, " make me cum you Bastard!" That's when rex went still except for his cock jumping. Suddenly I felt that warm river erupt from him. I came again as his doggie cum began to fill me. He gave me all his pups. Filling my womb, making my egg swim in the lake of cum. I came several times as his know stretched me. As this happens I heard mom cum on dad's cock. Me and mom both getting fucked. I remember thinking that I got the better. I wrapped my arms around Rex as I felt my lover inside my pussy. After that i left the vent open but left the boxes in front of the vent.