Pool jets are awesome! Discovered this early on and have continued since. We have an apartment building up the street whereby I would take a jump over the fence (outdoor pool), strip down and hold myself in front of the pool waterjet and let my dick bounce around until it exploded.
Once, I pulled this same routine in the summer to find the maintenance guy standing behind me. Ass bare and noticeable through the water he seemed to be enjoying watching me thrash around moaning and then ultimately ejaculating in the pool seeing the cum swirl away in the water current. When I turned around when the deed was done that's when I finally noticed him, bit embarrassing, he said nothing...put on my speedo in the shallow end, walked out with the post-cumming boner and left. Haven't seen the dude since, I like the idea that someone watched.