I've had all sorts of fantasies, a lot involving domination, but rape fantasies do nothing for me. Have someone do stuff to you you don't want and then have a rape fantasy, it's not gonna happen.
Having said that, I completely freaked out my husband when I told him I had been fantasising about blood letting and knife play (not being penetrated with a knife, just being cut during sex). He even gave me permission to seek someone else to fulfill that fantasy. I never did that and we managed to find a happy medium.