All right... SERIOUSLY? I dunno... I read this thread & I say "is this serious?"
You (not OP, a generalized "you") are a grown adult. As denuseri noted, you make a CHOICE every time you do/don't do something. Anything other than "you are an adult, you make the choice" is just psychobabble or "lifestyle babble"--which, don't get me wrong, is fun to listen to. But it's really just "justification" or "rationalizing" your choice.
Whether you are a Dom or a sub or a whatever you wish to call yourself (let's not get into a label war), you are responsible for your choices. Don't lay this at the feet of your partner & say "oh, it's their choice, I signed my rights over to them." What a crock of crap--you have the opportunity ALWAYS to make your own choices. Now, those people who say "I am his slave... I make no choices." WRONG. You make the choice to MAKE no choice--you defer to your Dominant--but that isn't "no choice"--that's MAKING a choice, though perhaps it isn't a choice that has a direct resulting action--it's a choice to give someone else the decision making power... but a choice nonetheless.
Look, here's my point. I think it's getting to the point in Lifestyle where too many people are making excuses for poor decisions/choices & behavior because they say "oh it was my Dominant's fault" or "oh, but I trusted him." You are just as much of an adult as he is!! YOU make the choice!! And on the other side, Doms need to empower the submissives/slaves/whatever to feel comfortable to speak up & communicate about things they aren't comfortable with.
Sure, negotiation is good, and yes, limits should be discussed. But communication shouldn't cease simply because a limits list has been filled out, or you had "the talk." Communication is ongoing. In good relationships, you will find the D & s communicate constantly... before/during/after scenes, during the normal day... there is a constant flow of information & feedback between the couple. Neither can read the other's mind, and neither should be expected to. On the same token, both are responsible for their own actions & choices-- what you decide to do is up to you.
If you don't want to do something... for shit's sake... don't do it! If it's something minor, you might consider that if it would make your Dom really happy, you might want to just give it a try. If it's major, the answer is: "Thank you for the opportunity, Sir, but no." The word no is a powerful word more people should try out.
There is a difference between being disrepectful & being a doormat.