First, I love reading all the stories of everyone masturbating so why not talk about it, right?
Well, my story is from a few years ago when my wife and I were in our early 20s. We used to go out and let guys get a look up my wife's skirt. It would get me all worked up and my wife would really get wet.
Sometimes, we would go to the mall and 'look for shoes'. My wife would be wearing a very short skirt with maybe a pair of very sexy sheer panties, the kind through which you could see her shaved pussy.
After doing this, we would usually drive around and I would start playing with my wife. She would take off her skirt or push it up around her waist, then take off her shirt and start playing with her tits. She would get so wet and worked up that she'd start masturbating in the seat next to me while I drove around. My wife would sit back in the seat and play with herself. Cars would be driving next to her; the trucks and higher cars could see right in and watch my wife masturbating which would make her cum so hard that we would have to put a towel on the seat.
Watching her masturbate in front of other guys in public really got me off, and I would usually start jacking off while I drove the car home. My wife would usually be totally naked by the time we got home and so wet. She would tell me how much she liked masturbating in front of other guys. We would have some of the best sex that night with both of us thinking about her getting off in public.