Usually a young male who has this odd habit of lifting up his shirt to wipe nonexistent sweat away from his forehead, revealing a chiseled six-pack. For some reason, this action always coincides with proximity to a young, attractive female.
I’ve seen women do this, but it's usually a guy thing. They're obsessed with multiple varieties of supersets and compound sets. Such an approach to exercise is admirable, but during busy gym times trying to carve out a fiefdom of several pieces of equipment that no one else is permitted to touch qualifies as douchbaggery. It's annoying to see one of the few bench presses abandoned for several minutes with plates still on it, and when you finally decide to go and use it, the Hoarder charges up, indignant, proclaiming, "I'm using that!"