I would make sure you have something in writing that both parties are agreeing to this fun playing. Whether it be email exchanges or a written and signed document.
Here's a news article about several rape fantasies that have gone really, really bad.
http://www.vocativ.com/underworld/se...orribly-wrong/
It is risky play. You can be arrested for assault, sexual assault, rape, etc. even if both parties consent to the plane. If police feel anything illegal was done, you're going to jail.
I had a girl from last summer that wanted things rough, very rough and when I took it as far as I could, she wouldn't even rougher. I held back.
Id get everything in goddamn writing. Negotiate this scene via e-mail, keep copies of those e-mails, and agree in advance — via e-mail — on a safe word that, if uttered, brings the action to a screeching halt. I'd also suggest that you — with her consent — make a digital audio recording of the encounter. Then you wouldn't just have e-mails proving she consented going in, but a digital recording that proved you stopped whatever it was you were doing if she used her safe word and retracted her consent during the encounter.
Making a digital audio recording of the encounter means you won't have photos or video to share over the interwebs, which should appeal to her if she is concerned about privacy. And using the magic of the World Wide Interwebs, you can simultaneously record this encounter on your computer and remotely on hers. That should give her some assurance that you won't take advantage of her written consent to a consensual rape-role-play scenario as a cover to actually rape her, i.e., to do things she hasn't consented to or to ignore her if she removes her consent during the act, because then she'd have proof that you ignored her safe word and kept going after she withdrew her consent.
I'm not denying this type of role-playing is very erotic and hot. Don't letting someone is a very good turn on, but your life and freedom is on the line. I wouldn't walk into the situation without doing a lot of research in preparation.
If your female friend ends up having bruises and gets upset with you for any reason, she can always call the cops and make a report. And what if you have no agreement in writing or recorded and after your role-playing, she goes to the police or hospital to report a rape?