In response for women who are into forced fantasies with an sexually abusive past, I have some articles on psychology bookmarked and this topic happened to be one of them.
Reaction to Trauma - This one is not mentioned in the paper, but Brett Kahr, a psychoanalyst who has conducted the largest survey of sexual fantasies ever, argues that most masturbatory fantasies are attempts to transform early difficult experiences into pleasure. So those who have been sexually abused may try to master their trauma by taming those experiences.
Source:
http://blogs.psychologytoday.com/blog/brainstorm/200805/why-do-women-have-erotic-rape-fantasies