with regard to everyday life, i say no all the time to normal stuff (although i don't really like to, i found i was beginning to get overwhelmed and was getting resentful. my bad really as He wants me to be myself and to take care of my needs) with regards to play no is out of the question with the exception of hard limits that W/we have agreed upon, or if i need to use my safe word. i have used it once in all the time W/we are together, and a half way word meaning i need Him to back off just a bit, but it is there not "no" that i have my way to protect my safety whether it be mental, emotional or physical.
that being said, i am accountable for how i speak to Him. i don't have to be a doormat, just respectful. this is how He has wanted me to be from day one. i think being true to myself within this is why i feel so safe with Him.