I have acted one of these out in a vanilla relationship (this is as close to kink as that ever got). The person I was with used some words that I was not comfortable with, but unfortunately, I did not realize that I wasn't until the scene was already happening and the words were said.

I was able to overcome the discomfort and finish the scene.

We then discussed those words and actions that made me uncomfortable and agreed to not have that happen again.

I have discussed my issues with this type of scene with Mia'Cova as well. He is aware of my issues and we will do our best, if we act out this kind of fantasy, to address all of them that we can before implementing the scene.

I think a safe-word is crucial here, due to the fact that unforseen reactions CAN and DO occur. Especially if you are the victim of abuse. You may think that you're over it, but things like this could trigger additional memories, etc. that you may not be prepared to deal with. If you have any concerns at all: talk, talk, talk, then talk some more.