Holey cutoffs.
When I lived in New York City I used to run around in a pair of very worn cutoff blue-jean shorts that was full of holes. The shorts after years of wear barely had a crotch any more. One of my favorite things to do was go to a coffee shop in the neighborhood, order coffee or breakfast and flash people under the table. It was very easy as I was sitting there hidden by the table to whip out my hard dick and bounce it around for anyone across the room who might want to watch. Anyone standing, like the staff, could not see it. You had to be seated at a table placed across the room to sneak a peek.
I have a couple of pairs of very short and holey cut off denim shorts too, I like to wear them around my allotment garden when other people are about, I know that sometimes they get to see some of my bits and pieces but I didn't care, so far no one has said anything about it I think they just find it fun, when nobody is close enough to see I often put my over long tee shirt on and remove the shorts and go bottomless, it's not as much fun as going nude but it's still fun.