Long Trip

My family seldom took summer vacations, but when we did, it involved a long road trip to an aunt's house in Florida. Before car air conditioning, the dads always wanted to travel in the cool of the night, so we would leave before dawn, my sister and I still in our pyjamas. We carried so much stuff with us that some of it was put on the back seat with us and my sister would ride in my lap until we stopped for breakfast. On the one road trip we took during my adolescence, I at first objected to my sister riding in my lap for so long, but it did no good. We slept for a while, until I woke up with a boner. It was still relatively short at the time, so I didn't think my sister would notice. Through the motion of the car, she did end up sitting directly on my little boner and I was totally embarrassed; but she didn't say anything. So, I tried to reposition myself, thinking she might still be asleep. Well, when I got her moved so there was no contact, she moved back and whispered she was more comfortable that way. I thought it was odd for her to say that, but it did feel good, especially since all we had on was thin summer jammies with no underwear. I didn't know anything about clits or girls orgasms back then, so I thought it odd that she kept moving around until my cock was rubbing against a certain spot on her. Bravely, and still taking my chances, I thought, I asked her if that was better, and she said yes, while the rough road and stiff shocks provided some amount of motion without obvious effort on our part. She spread her legs wide apart and leaned forward, putting her head on the back of the front seat. I could feel my cock pop out of my fly, and she must have been able to see in the dim light. I felt her fingers softly rubbing over it. It was the first time anybody else had touched my boner and did it feel good!! With Dad driving and Mom asleep, my sister got real brave and decided to turn and face me, while sitting on my now bare cock. Her pj top was kind of long, so she pulled her pj bottoms down to expose that bald slit, and that almost sent me over right there. And then she sat on my cock, causing it to aim up at my navel. I knew what was going to happen, so I raised my top up so it wouldn't be hit. I kept one eye on the parents, while she continued to stroke my cock with her pussy, but it was difficult to see. She didn't move a great deal, and she didn't need to. I came after a very short time and I grabbed her hips and held her tight to my cock as it spasmed spurt after spurt of the white stuff. That was one powerful orgasm!!! If the car windows had been closed, I am sure my dad would have smelled it. So, without a tissue around, I just smeared my jism around to make it dry faster, and my sister helped!!! Because she did that, I never even got soft. When I was dry she leaned forward on me and said, "Do it again". She remained lying on my chest, so I put my hands on her butt cheeks and started moving her again. She got the idea and sat part ways up, leaning her hands on my chest, and started grinding again. I moved her hips so that she would ride up and down on the bottom side of my cock. It took a bit longer, but I did cum again, just not as much volume. We repositioned our pyjamas and resumed our sleeping position for the rest of that leg of the trip. When we ate breakfast, we were able get rid of some of the boxes, and so she didn't have to sit on my lap any more, to our disappointment. BUT, when we returned from the vacation, we began to more fully explore "things", and to have a great relationship all through the teen years.