I was watching an episode of "Law & Order: SVU" last night with my slave, and the story brought up some interesting points. In the episode, a woman who had done rape fantasy porn had two men corner her in the bathroom at a party and treat her like she'd been treated in the movies she'd done--but without her consent. There is no question in my mind that it was rape. No matter how she'd been treated in films, she had always given explicit consent. That's how the industry works--or should work. The "victim" in the film is aware of what's going to happen, and she can stop it at any time. With the young men who raped her, there was no discussion of safe words or hard limits. I find consensual non-consent hot, as does my slave, but we still enforce hard limits, and a safe word will still stop the play.
In the absence of safe words, "No" and "Stop" are your safe words. Absolutely. Beyond a doubt.
The rape victim didn't get justice, though. The defense attorney used her film work against her, saying that the only difference between what happened to her without her consent and what happened on film was that she didn't get paid. No, that's not the difference. The difference was lack of consent. The difference was a lack of discussion of limits and what was going to happen. Sex workers are not exempt from rape.
That's not really the point I wanted to bring up, though; what went on in my mind was prior knowledge of the sexual activities of submissives--and dominants as well--and how it applies to subsequent BDSM activities with new partners. Some people might have it in their mind that because a submissive or dominant did something with a previous partner, that activity is on the table in the current relationship--but it's not. There still has to be consent. Maybe your new partner isn't comfortable doing that thing with you. Perhaps your lack of experience, lack of knowledge and/or responsibility for safety, or lack of skill (you can have experience without gaining proficiency) makes your partner uncomfortable with a particular act. Maybe the trust has not yet been built.
In short: nothing a person has done in the past with kink gives you an excuse to coerce that individual into the act with you. Consent is essential. The comfort level has to be there.
I've done a lot of things with previous subs that required a lot of trust--dangerous things that could result in serious injury, infection, or even death. That kind of trust doesn't come easily for most people, submissive or dominant. Purely from the dominant perspective, there's the consideration of trust where marks are concerned. Where there's evidence of BDSM play, there's also a potential domestic violence or rape charge. Being able to trust your partner not to have you arrested takes time--sometimes. Some people are able to gain trust more quickly than others, but the bottom line is: if you don't trust your partner with a certain kink, you shouldn't engage in that particular act--and by no means should the other person pressure or coerce you into it.