As Mistress Florence indicated the storys that are so erotic and extreme of the BDSM kind are just that, stories. The term SSC or Safe Sane and Consensual has merit, and since your new to BDSM it would be in your best interest to stick with that mentality. As you indicated in another post your looking for implicit trust with a Master, when you reach that trust, he is going to know your limits, what would be pushing your limits, and what you just cream yourself when he does to you. So worrying about not doing or doing something with someone, well it's best to discuss what you expect, as well as what he expects. Remove any doubt as to what would cause you to seek legal matters if he were to do it. Google acivity checklist, fill one out, and as your experiences grow in BDSM review it, see how your limits change, or not change, and what your expecting out of play.