BDSM Code Words, Ambiguity, & Safety

Yesterday, a lady came into the Submissive Women's forum I frequent with an issue:
On previous occasions she and her partner had discussed anal play and she had expressed a disinterest in it, I believe her exact words to her partner were "I'm not interested in that."

For most folks, I would hope, that would be a pretty clear indication not to pursue anal play, but her partner decided that while she was spacing to fiddle with her bum... She is, to say the least, unhappy and feels that he might have broken her trust.

Many people advised the OP to make anal play a hard limit.

Today, another lady started a thread questioning why "I'm not interested" wasn't enough and why someone should have to make something a hard limit to have their reluctance to participate in an unwanted activity respected.

It started me thinking.

There's an idea floating around in the Kinkyverse that "no" doesn't always mean "no." We sometimes have safe words so that we can participate in play where we want to protest or say "no" without play stopping. Sometimes play won't stop until a safe word has been used. Safe words and the sometimes-ambiguity of "no" is such a big deal that there are a plethora of blogs written about it... A BDSM code word is required to stop play.

So we've got this idea that plain English isn't serious and we need to use a code word to express how serious a "no" actually is.

Thinking more, I wondered if the "no doesn't always mean no so have a safe word" school of thought might be affecting other plain-spoken communication. Communication your average submissive would expect to be heard and respected by a partner?

It's not impossible to imagine that someone who is hung up on safe words and play involving protest might view "Hard Limit" in the same light... "I'm not interested in that" could be seen as a faux protest to that person, leaving them with the feeling that it's OK to try that activity because they didn't hear the unambiguous "Hard Limit" code word to indicate that anal play was definitely off the table.

The code word makes what previously would have been seen as clear communication ambiguous.

It's really effing complicated.

But I suppose having heard about it, it's something that s-types and D-types should be aware of, and discuss before playing, because having your butthole diddled while spacing is a pretty tame activity when compared to some of the shit we can say "I'm not interested in that" about.

So...

S-types, just to be safe, it might be a good idea that you communicate to a new partner that when you express a disinterest in something you mean it. That disinterest is a hard limit until you say other wise, "I am not interested in that, it is a hard limit."

D-types, also to be safe, it might be a good idea if you ask a new partner how serious they are when they express a disinterest in something without calling it a hard limit. It might be protest play, but it might not... And if it's not? If you go ahead without consent, you both might end up feeling pretty awful about whatever happened. Nobody wants that.