the worst i've ever done was jerk off in a public restroom stall back in high school. i even did it regularly for a while, i would "need to use the restroom" to take a piss... and then beat off for 10 minutes. i got better at cumming quicker so no one would suspect (even though they probably did anyway) but eventually i couldn't keep up masturbating intensely enough in a short time period so i had to stop. that, and also the fact bathrooms fucking reek turned me off from it.