I'm sorry, I was just having a little fun with that description. n.n It's not a literal on-off switch; should her more assertive lovers yank on it, she has an extremely strong emotional/sexual response, but only because it is they... she doesn't respond that way to just anyone. She's rarely embarrassed by anything she does with her lovers, though like most people she prefers to keep that separate from her more public-facing activities.
That being said, Cynthia does have friends who enjoy playing with mind control, and she can be occasionally convinced to let her personality be interfered with by those she trusts. And then they go out and buy slutty clothes!

