I was 14 at the time.
Night time had come around, and my family and I were driving back from the hospital. At the hospital, as I sat in the waiting room, I came across a health magazine. On the cover was a gorgeous girl in a green swimsuit. I ripped the cover out as discreetly as possible and stowed it into my backpack. In the back seat of the car, I pulled it out and took a gander at it. I was instantly horny.
The windows were open and the lights were off; it was the perfect moment. I slowly unzipped my pants, grabbed onto my underwear, and pulled them both down to my knees.
I grabbed onto my rock-hard penis and began to slowly stroke it. I held the cover of the magazine with my spare hand, and as we drove, the street lights illuminated it. I continued pumping as I held my deep breaths back.
A few seconds later, I orgasmed. Quickly I pinched the tip of my penis so as to avoid ejaculating all over the floor. I asked my mom for a napkin and used it to clean up all the cum. I then stowed the cover in my backpack and slipped my pants back on.
What a car ride!