Would you call a dominant you've just met, "Master" if that was their preferred title? (not in your case specifically, fetish...forgive the gender specifics, please.)
I mean...if trust, time, energy goes into a M/s relationship and you've met this dominant once or twice and played very lightly, would you?
And if you did...would you be doing it in order to not bruise their ego or because you can absolutely use that term as just what fetish implied...a simple title?