I can fully understand where you are coming from jeanne, at least I think I do. I don't know your specific situation, nor is it my business either.
But in what I have read, my circumstances do fall into the general meaning of your questions, so I'll give you an answer based on my thoughts about how I am trying to deal with my own situation.
I fully believe in having that clarity to know where you stand within the relationship.
I need it, if only for my own peace of mind. I need to know that I am significant and that no matter if I am the second in his life or if he chooses to bring in other submissives into the mix, that I still know where my place is and that I am still significant to him.
Things do change and they always will. Time factors, commitments, responsibiliities and such can change the course of the relationship over time, it can at times move you out of the comfort zone and mix up your feelings.
I want the clarity, but I already had that in the beginning. Sometimes I want it revisited, but really in the end, it will come down to the same thing as it was in the beginning.
I have a collar, I am owned, I am his, but for me sometimes there is a grey area that I can slip into without even trying.
I know where I stand, but at times other factors get in the way of what I know and it's a matter of dealing with them as they happen.
I can't control everything, but I can control who I am and where I am headed. If I feel that I need to revisit my place, then I will do so, but I try my best to understand that he gave me a place, and that place is where I will be until he tells me otherwise.