Said person generally has a fetish(es) seen as abnormal to the public, ie. biting, bondage/bsdm, public sex, spanking, tranny sex, etc.
Shy girls tend to be, although surprizing to the male population, kinks.
B: No, she's a pretty big kink. She lets me tie her up and give it to her up the bum.
"im going to go see chunk no captain chunk this weekend!"
"wow grant! your suck a fucken kink!"