Hi, I was wondering if anyone else ever had a similar experience as me. It has only happened occasionally but sometimes when driving on the highway or particularly fast the vibrations of the road would shake the car seat and my dick so much to the point that I was afraid I was going to cum. I nearly reached climax while completely soft. For some reason it does not always give me a pleasurable sensation only when I seem to focus or relax my body. At the moment this was horrifying as I was with other people in the car, but now it intrigues me and I want to try to replicate it. Has anyone else had a similar sensation?