Thanks for the comments guys. I hope I can inspire more people to shoot a load on some unsuspecting sluts!
Unfortunately I don't have any more pics. I'm mostly a frotteur, and have cum on tons of girls in crowded situations, however getting pictures is usually pretty difficult.
For anyone interested my stealth masturbation technique is to have a shoulder bag over on side with one hand underneath the bag jerking off, and holding something in the other hand (sweater etc.) so that it blocks the view from the other side. This way it's difficult for anyone to see what i'm doing. Especially if it's dark, and in a crowd most people can't see below your waist anyway.
These pictures were from an outdoor festival in the summer, it's a lot harder to find places to do this in the fall/winter so I doubt i will have any new pics any time soon.