I say, "no," to M frequently, and by 'frequently' I mean 'all the fucking time.' As of late I have switched it up a bit, interspersing my 'nos' with 'nays' (Surely I am not the only one who, after a medieval historical fiction binge, finds themselves sporadically speaking like a fourteenth century noblewoman?), and I often substitute with a 'fuck off' or a 'hell no,' depending on my linguistic needs. At times my 'nos,' 'nays,' and 'fuck offs' are accompanied by a slap or a scratch, and occasionally I am known to pair them with a kick in the direction M's shins (What can I say? I prize both clarity and directness in my communications, verbal and non.).
I doubt many masterful-types would permit the sort of behaviors that are readily accepted by M, but I am fortunate enough to have a fairly laid-back owner, one who is largely unintimidated and unperturbed by defiance or by my big mouth. He has no reason to be, and he knows it. Half of the time I am doing as I have been told, even as I shout, "Nay, you treacherous scoundrel!", over my shoulder, and, in the event that I am not doing as I have been instructed, it is rarely too tasking for M to force my compliance. This may be achieved any number of ways, ranging from shooting me a look that is sufficient enough to make me fear the potential consequences of continued refusal and reconsider, to beating my ass until it glows and then physically maneuvering me in to completing my given orders. Given our vast size differential, even the latter is relatively easy for M to accomplish, meaning that M is never without recourse in the face of the defiance that he allows me to exhibit. I imagine that there are times when M wonders if speech restrictions, or perhaps a brank, might be of use, but the honesty that is fostered by the freedoms of expression that I am granted has thus far outweighed the drawbacks. In addition, the overt and tangible reinforcement of our relationship roles serves to strengthen M's dominance over me, regardless of any protests on my part.