"How did you discover you were kinky?"
Loaded question. This, to me, is like asking someone homosexual "how did you discover you were gay?"
Some may answer with a description of a pivotal moment, a turning point in time when they suddenly realized they were gay. But for others, the answer may be, 'I always knew I was gay. I just didn't know what that meant.'
I think, when it comes to kink, I fit into the latter category. I always knew I liked things 'different,' liked things 'heavier,' but I didn't always have a word for it. I didn't know that made me 'kinky.' And I didn't discover BDSM until I was much, much older.
Of course, girls, I think, always have a harder road to go down to discover their sexual preferences, simply because sex itself is a much more complicated issue than it is for boys. Certainly when I was a kid, and I think to a certain extent even today, girls face repercussions that boys simply don't have to deal with when it comes to having sex. Aside from all the medical issues, they have to worry about coercion, reputation, bullying, stigma, etc etc.
If a guy has group sex with a bunch of girls, he is envied by his friends. If a girl has group sex with a bunch of guys, she is a slut. Now, some will say that being a 'slut' is okay, and some will wear the label with pride. But not many will stand up and say, 'no, she is not a slut, she is a normal girl having fun.' (They will not say it and then not somehow backtrack on the statement, anyway.) A boy who has sex at a young age will see pride and satisfaction in his father's eyes; a girl will see derision, disappointment, and a need to hide her away from the rest of the world. Ask a dad, and most of them will tell you this.
To get back on track here...the point is, it can be much harder for a girl to discover her kinks, because it takes her longer to get comfortable with her own sexuality. Once she does, she may discover she actually likes to be tied up, or tie up others, or like different positions...she may want to experiment, play, bring props to bed...and then it all depends on her partner(s), and how open they are to that sort of thing. If she's really lucky, she may meet a partner or two who can tell what she's looking for, someone she can share her fantasies with, and then get the ball rolling from there.
Well, this post certainly took a turn I wasn't expecting. Maybe I'll revisit the original question again at some later date.