SWEATY BALLS!!!
me and this dude i met (this was years ago, mind you) were at his place, started to fool around and such, i start to undo his pants and i got one wiff of stinky sweaty balls..omg i thought i was gonna fuckin puke.
he must of had a problem or been jogging or something. for the most part, he was clean cut, handsome, well-maintanced/groomed. Never would have thought... *gags*