Do you say MR. MS or MRS. at black belt?

I have a respect question????? I know in our Dojang and several others that i have trained with down through the years, At black belt we have always called the black belts and higher by Mr. Ms. or Mrs and thier last name out of respect for rank. Do you do this at your dojo/dojang or school /academy??? the reason for this question is that i was recently at an open tournament and a Kempo "Master" had walked out on the floor while i was judgeing and called Kris, I thought nothing of untill I had called hime by his first name and he sharply corrected me by saying "thats Master L^^" and so I sharply back replied "well then its MR. Mc^^^^^^ ".. He informed me that in his style they didnt recognizethe fact of calling MR at black belt. so I replied to him then I dont recognize you being a master. I know this sounds childish but dont you think that respect is deserved not only by you but also from you. So abck to the question at hand? Do you say Mr at Black belt??? and if not why not? There should be respect for those who have trained hard.