My record is 7 times, but some of these were during the early morning hours.
When a freshman in high school I shared a bus seat with my g/f. The ball game was a 45 minute drive from our home town and coming back after the game, I had my knees up against the back of the seat in front of our seat and my rain coat spread out over the lower sections of my g/f and myself.
She had her hand just a little below my right knee and her head on my shoulder. With the bus's motions her hand gradually slipped down my upper leg making me hard. Since I was hard, I took her hand and placed it on my cock. At first she didn't make a move, but soon began to squeeze and push on it. I unzipped my pants, took out my cock and she began jacking it.
Since it was raining the driver took each of us to our door, so there was no getting any sex to finish the job that night. I headed for the bathroom as fast as I could to jack off. After the third explosion with the same hard, I managed to get to sleep but woke up four times having to masturbate myself during the night.
The dawn's early light was up for the sixth and seventh times for my hard on's eruptions.