One time maybe 2 years ago I had a very strange dream that disturbed me. In the dream it was like I wasn't myself, but in someone else's body without being able to control it. I'm a woman, but I was in the body of a man in all black clothes, I broke into an apartment and it turned out to be where my sister lives. (In real life she lived with me at the time) Then I raped her- having no control over the body, like I could only watch what was happening. This dream really creeped me out and it makes no sense to me, what do you think it means?
Rape dreams are often about power and control. Maybe your sister in your dream represents an aspect of yourself that you would like to control. The fact that you had no control over your body emphasises this.