With that, she slowly and gently climbed off my lap. She was well aware that silence was the highest priority. And she was silent and cautious with every move she made. Then she slowly got down on her knees. Her body was flexible and agile. Squeezing down between the seats wasn't a problem for her.
And there it was. My sister was on her knees. Naked. Looking me straight in the eyes. She held my hard cock with both hands. It was then that I finally appreciated how soft and delicate her fingers were. They felt heavenly.
But that was only the beginning. She bent forward and took the head of my cock in her mouth. With her lips wrapped around me, she used her tongue to expertly swirl against the tip of my throbbing erection, which was a sensation I had never felt before. And it came from my sister of all people.
Our eyes were locked together. That was when she lowered her head and took most of my shaft in her mouth. One thing was for sure- she knew exactly what she was a doing. My sister was a pro at sucking cock, and I found out through firsthand experience. Her head bobbed in a calculated motion. Her hands were in sync with its stroking. Her tongue was in the same alignment. She sucked my cock with so much enthusiasm and vigor that she had to use her fingers to tuck her hair behind her ears. The feeling in my cock was near the point of agony. I had never been so stiff in my entire life. But luckily, my sister's skilled mouth was up to the task.
At one point, her phone made a beeping noise. Without missing a beat, Christine picked up her phone, with my cock still in her mouth, and she began to text. It was almost comical (and super arousing) that my sister would text while sucking cock. It seemed like something she would do. I wondered who she texted, and what it was about.
While her mouth kept on sucking, I wondered if she was texting with a friend about upcoming plans. Maybe the latest gossip? Or maybe she was texting with mom? Maybe she had been texting mom the entire time. Christine had recently taught our mom about texting, and they had been texting buddies for the past two weeks. I keenly remembered mom saying that she wanted to know how things were going in the morning. It had to have been mom.
I imagined my sister texting mom about how our trip was so much fun, and that we were having a blast. All the while, my throbbing hard cock was in Christine's mouth while she sucked expertly. Not to mention I had just given Christine a powerful orgasm with my fingers.
The thought of it was too much. Between those nasty taboo thoughts and my sister's mouth, I was ready to explode. My hips bucked. Christine knew. She sensed my weakness, put the phone down, and winked at me- letting me know that it was okay to cum in her mouth. That's when I did it. I shot several loads of cum, deep into my sister's mouth, down her throat, and into her stomach. She stroked proficiently with both hands. Her lips remained tight. She swallowed everything that I shot in her mouth, and it felt glorious. And there was no doubt that she thoroughly enjoyed swallowing every drop of my cum.
When it was over, she made her way up and sat down on the seat. She continued texting as if nothing was wrong.
"Thanks for the little 'snack'. You taste really good. Let's hope your cock dries before the rest stop, or else people will know that we've been very naughty back here."
She continued texting as if nothing was out of the ordinary. I saw her lick her lips, tasting the remainder of my cum. It was a surreal moment. And incredibly erotic too.
"By the way, who are you texting?"
Christine smiled, "Mom, who else? She won't stop asking about our trip."
Just when I thought our backseat fun was over, I found myself becoming aroused again. Suddenly, I was in need of more sisterly relief. And judging by the look on Christine's face, she needed more also.