"I saw Lisa blush; I did not know what to think. Dad was cheating on mom with his own sister, was giving me my half-sister Lisa and that made my cock ...ard."Lisa take Mark to your room and stay there. I am going to fuck my little slut sister now and don't want you kids around."Lisa took my hand and lead me to her room in shock. This could not be happening, my dad had a mistress and she was dad's sister, and dad swore, damn. Lisa's room was a typical High School girl room. She had pictures of. I pulled her back close and said, "You are really getting into butt fucking?"She wiggled hard on my erection to settle it as deep as possible in her ass. "Yes, I had never done it before but I love it. Fucking is so good. I want to try a double penetration soon. Becoming your slut was a great decision for me. Everything you've had me do has been fantastic. I wouldn't have thought to do some of it but it's so good. You like anal, don't you?" Yes, an asshole stays tighter for me. I know a girl is. I have an adorable little jean mini skirt that laces on the sides, and a really low cut halter top."What do you think?" It's nice, but we may have to work on it..." Charlotte says."Let's come to my house after school tomorrow, okay?" Sounds good," Char says."Okay, should I bring anything?" Yeah, bring the sexiest thing you have." Whoa there..."They give me a look."Okay, whatever you say."We all start laughing."Okay, time to pick up the guys."We drive over to Erin's house, and find them all. ” “Well try not to think about it. Just be happy with thetime we have.” “Jo, I can’t get over how great you are. Your my best friend,lover and cousin. How could anything be better.” She giggles , “Samehere cuz, same here.” She kisses me again , takes my hand. We walkhome. Talking how great today was. At home we eat then watch TV. I don’t remember a thing about anyshow because Jo is all I can think of. Bed time rolls around Jo says shegoing to bed. We all wish her a good night. Then dad goes.