Once in a while, a creator of something may want to give their fans a bit of Fanservice. He or she does so, and waits to see their fans get turned on... ...oops. Turns out it did the opposite. A case of Dude, Not Sexy! can happen due to the art style, a fetish used that the creator thought would turn their viewers on as well, the character(s) used, or maybe the fans wouldn't think fanservice would be appropriate for the story. This is NOT Fan Disservice, where the creators purposefully turn their viewers off.
Hello, Unknown Troper. You'll need to get known to lend a hand here.