Cause of Rape Fantasy

I hope I am posting to the correct group, if not pls direct me to the
correct source of information.

What I would like to know more about is the following:

A few years ago a woman I went out with told me she had a fantasy about been
raped and asked me to act it out with her, I decided to rather not because
it just does not seem right.

Now what I would like to know is what would cause her to have a sexual
fantasy like that, is it purely just a fantasy or is there generally a more
definite reason why someone would have a fantasy like this which could stem
from a case of abuse or a forced sexual act over which they had no control,
and if it is so how badly could it affect someone?

She did mention once that she was forced to perform oral sex on someone when
she was younger before meeting me, did not mention age when it happened I
think she was 14-16 years old when it happened, but basically she was held
down and made to do it.
How would this affect her in life over the years if she did not go for help
both psychologically and criminally.
She does have a normal sex drive but there was a time when she would become
confused about her sexual nature seemed from a religious nature, but I
notice she can be very cold in her dealings with people and holds things
against people for quite awhile, and seems to like controlling situations
and would rather pull out of a situation when confronted than talk to a
person because it seems like she does not want to face a person to tell them
because as she says it is easier to ignore a person.

I would just like to get some kind of input into this situation because I
would really like to know what is going on because she holds somethings
against me which are small things but she blows it out of preportion, as I
can't get myself to tell her I am not the one that did anything to you, I am
not the one that forced you, so why treat me so coldly.
This does not seem fair to me.

Could somebody possibly help me understand what is going on, or is her
behaviour partialy normal, does not seem like it to me.She can be
manipulative, has used people for personal reasons (financial: due to
current situation)and I feel me for emotional support and when I give it to
her she runs away again,leaving me feeling like a spare wheel( the
proverbial kick in the teeth), likes to be in control and if not in control
and gets pushed for something retaliates quite harshly.Yet she can be such a
wonderful,warm person, is a perfectionist.
Makes it seems like she still loves you and then makes it looks that she
does not by staying away from you and been with someone else and then
thinking again to herself that she does like you but needs time, what
confuses her like this. It has put a lot of strain on me and I cannot take
it anymore, we have both said harsh things to eachother lately and we are
not talking to each other at this moment, ignoring each other, because it
seems better that we rather stay away from each other at this moment?
Is something more wrong than what it appears?
Sorry for the elaboration but it seems better if you get a better picture of
what is going on.

I just have to understand what is going on, can't ask her because she does
not talk to me, I want to know is it possible that after all these years is
it still affecting her and how? This is bugging me and I need to understand
if it is possible that it is affecting her before I call her and speak to
her , I need a better insight into this possible reason for her general
behaviour.

TIA