Reply: Jerked off in the backseat

Was visiting my sister and her boyfriend at the time and we decided to go to dinner and a movie and my sisters boyfriend offered to drive us all in their car.
I sat behind him in the back and my girlfriend next to me. It was getting late and the drive was really long like 45mins one way. My girl lays her head on my leg and brings her right arm up an under my leg like shes cuddling my thigh. My cock begins to grow an swell because her hand starts slowly sliding down my inner thigh towards my cock and Im wearing shorts so she slips her hand inside my shorts and begins teasing my head and rubbing my shaft over my boxers.
The sensation of being rubbed over my boxers was insane and doing it in public while other people were driving made my cock so much harder and so horny. Her motions quickened and i looked down and her and was getting ready to blow my load so I squeezed her left shoulder a lil bit as a warning and next thing I know Im blowing my massive load in my pants and riding that wave of euphoria from cumming so fucking hard.