Definitely a coiling, roiling bush! When did all this fetish for shaving (especially totally bare like a child) begin? Just a peek of bush turns me on - love to see it curling out from briefs, jockstrap, or swimsuit, refusing to be tamed by garments.
And a guy w. a sprinkling to a full forest of hair on his ass - especially around the "epicentre" - is dizzying. Maybe it was all that Greek mythology I read in my youth: those satyrs and centaurs all over the place...