I have a few pairs of pants with holes that allow this favorite pastime, playing pocket billiards but not masturbating. I have done it in all sorts of public places, including queues at supermarket checkouts. One pair of pants has the whole bottom seam of the pocket torn, so my whole hand goes through. I just have to remember not to put my wallet or change into that pocket. I have sometimes had to pick up my wallet from the floor after it falls out the leg of my pants.
I also have a pair of jeans with a hole in the side of the pocket. I can pull half my cock into my pocket and hold it in my hand, which feels good when among people. If I get a hard-on I must be careful to keep the top of the pocket covered so that bare skin is not seen, rather than VPL.