Master Evan and I have a long-distance relationship, primarily through IM, so it can be very difficult for him to know how I am feeling unless I tell him.
Recently we were involved in a scene where he had my body responding so strongly I was struggling to breathe (no gags involved) and couldn't type to tell him. The garbage I sent eventually helped him figure it out, and he called a stop. We discussed it afterwards, and now I have a simple safeword I should be able to type, even in that state. I knew they were important, but realized just how much now.