Fucking my Sister where we couldnt be seen 3

Once started when we had to pack into our Uncle's truck from his place back into our little community. T was left out but said ill sit on brothers lap.

It was a crew cab style that had two fold down seats on each side.i managed to get in back when they packed it with boxes of cooking pans n pots leaving one fold down seat. I took it but older stepsister T wanted to ride back and said ill sit on my lap on way back.I had been noticing my sister alot.Especially when she wore her shorts,I mean short shorts with her bottom ass cheeks showing when she bent over.I would jerk off at home thinking about her and her big heavy juggs. And they were some big knockers.When she played around with me and my other stepsister I would let them kinda wrestle around with me just to let them rub against me with both big tits they have.And Id get a feel their legs too.I get hard and I know they noticed. Well when she got in she backed in with her ass first.My God the view she gave me of her ass up in air,ass cheeks showing alot more than usual and her panty lines showing a bikini style.She sat right on my lap and got comfortable. I knew my cock would get hard and I tried to fight it but it was a long way to go and it got dark.Didnt help when she shifted her ass so she was facing the front of the truck and the seats faced opposite directions. She made me hold her around her waist being a dirt road.Didnt take long before she moved around her nice round ass on my crotch.I couldnt help it but get my cock hard and her ass right on top of my cock.I know she felt my dick was hard with it right on her cunt.Those shorts were thin silk shorts.She just looked back at me and smiled like ,"Its ok and stayed right on my hard cock . After that I let her wiggle and slide back n forth practically leaning forward where I got a great view of her ass that I put my hands on her hips and helped her rub her crotch on my 71/2 cock thick and veiney.Threw her head back at one point and let out a moan I could hear but nor up front. I