My sister was in his lap facing the door. She had on no bra and a thong. She was giving him a lap dance. He was in his underwear and was obviously enjoying himself. Her long dark hair was down and he pulled it aside kissing her neck. She was rubbing her ass all over his cock…snapping her hips back and forth like a stripper. I watched his hands slide up her body and rub her nice round tits. He was moaning and she started moaning as well. I was horrified and yet soo turned on watching them. His hand skimmed her belly and dove into her panties….She moaned in pleasure, and he slid them off.
I found my own hand creeping into my panties. My pussy was already wet. He rubbed his finger up and down her wet slit, and he started rubbing her. She kept moving her ass on his lap; He smacked her clit and slid his fingers inside of her. Then he took off his underwear, turned her around and she started riding him. My hand was stroking my clit hard now, and I couldn’t take anymore so I ran to my room and started playing with my clit. I got my vibrator out and made myself cum over and over. I turned over on my hands and knees and rubbed my clit..When suddenly Grace (my sister) walked in with no warning.
“DAMN sis, what got you so hot?” I covered up quickly, but I was not quick enough. She laughed and sat on my bed.
“I am guessing you saw me and Mike fucking huh?”
I said, “How could you do that to mom?”
“I know D. But honestly, he is the best fuck I have ever had. You gotta try him out, if it would make you feel better, we could share him. “
I was shocked. I couldn’t imagine, yet at the same time, I wanted to so bad. She gave my tits a squeeze and said to think about it. Dinner that night was a charged affair. I went to bed early and rubbed my pussy till I orgasmed over and over just thinking about Grace and My stepdad. I decided to try it. I told Grace the next morning I wanted to do it after school. She said that we would surprise him.
The day dragged by, but eventually the end came. I was so nervous and so fucking hot all day that I almost had to go to the ladies room to rub my clit during lunch. She told me to go to her bedroom and wait. I heard her coming up the stairs with Mike in tow.
“Oh quit complaining, I have a surprise for you baby” she said to him giggling.
“I am sure it is a great surprise, but I am horny and want to fuck”
He walked into her bedroom and looked totally shocked to see me sitting there.