rmediver2002 bubbled: "(of course it is funny when you do it to someone else!!)"
Ya, we had one of those on a dive charter last year.
He comes up behind you grabs the zipper , yanks it open "say what kind of drysuit underwear are you wearing?" he fakes a look then yanks it closed, but just an inch short of course.
He made a tactical mistake though, I saw him pull this trick on another diver, and he's half my size, so when he approached me from behind, I turned, put my hands in his arm pits, squatted, raised my arms, and leg pressed him over my head and the rail of the boat into the drink. Fortunately his shoulder zipper was closed.
Mike D