The ways of the vanilla are a'changing.

"BDSMers" tend to call "vanilla" what should be called "strict heterosexual sex", and by extension they often also call "Vanillas" those that engage only in that kind of sex.

Sometime, with a somewhat depreciative under-tone... mostly when talking about "vanilla" males.

On one side, it is because a lot of BDSMer tend to over-impose on the "vanilla" category their bad experiences with this or that "hetero-normativist" (usually, their fathers), and conflate the ones with the others.

But a second reason may be that, as seen from a BDSM practitioner point of view, a ton of "vanilla" males could be as well called "cheaters" - as in, they tend to cheat in the "game". 

There is not  much to say about it... vanillas have it somewhat different from full blown BDSMers, when it comes to establish the consent of their partners.

First thing first, many vanilla men do not see any reason why they should not shag a plastered woman that they just met.

She is drunk? Her fault.

Of course, this doesn't sit well with the conscious BDSMer.

I should remember the reader that is not into it, that one of the BDSM golden rules is that no action should take place if any of the actors is under influence and has his mental faculties impaired - be the influence that of alcohol, cocaine or any other drug.
This, mainly because BDSM practices are often dangerous activities - dangerous like, say, climbing a mountain - that should never be tackled with less than full mental capabilities, and at least a modicum of training.

Also, a lot of "vanilla" males do not seem to mind much the whole "informed consent" side of things either... you get them to spread their legs, one way or the other, it is all good.

And, finally, they hardly even take a no for a no. Again, this is kind of at odd with the "rules" of the "game", as perceived by a BDSMer that's worth the definition.

I may be too harsh, here... and too blinded by my personal tastes and affiliations.

Many "BDSM" males would likely be happy to play by the same "rules" of the "vanilla", if they could... but there is a hard-wired difference between "BDSM" and "vanilla".

In most cases, vanilla sex doesn't leave lasting physical traces - which is one of the reasons most rape accusations aren't even investigated.

If the victim doesn't allow the use of a rape kit, chances are that by the time she manages to overcome the sense of shame  - and the fear of being re-victimised by the tortuous paths of the justice system - enough to log a formal complaint, physical proofs will have disappeared.

On the other side, in most cases even the most consensually established BDSM activity leaves physical marks that can be seen for quite a while more... the victim has some more time to reflect, and come to the conclusion that it wasn't all good and well in that session.

So , it is not that the BDSM male is more virtuous than the vanilla one... it's that it is somewhat easier for him to be charged for assault and battery, if one fail to get the partner's consent in a way that convince the partner that it was freely given.

From this derives some of the most curious habits of the discerning BDSMer, like asking - relatively often, and even in the middle of the scene, when the sub is all but floating in her sub-space - their partner if all is well and if they are still decided to go on.

Now, I will admit that, in this, my "vanilla" friends may be right.

Asking ten times, in an evening, to your partner if (s)he wants to go on may feel a bit clumsy and a bother.

But, curiously (or maybe not at all), it is also what seems to be bound to become the norm in college campuses in the USA, if the "[Only] Yes Mean Yes" campaign - and similar initiatives - takes root.

College authorities, faced with a growing consciousness by the general public that much of the sex that happens in their dorms is of the "fast and loose" variety (unintended rape, near-rape, full blown rape) are now resorting to the kind of ethical trappings that the BDSMers had to resort to.

If these will become the norms for every kind of sexual interactions between adults, then I see one reason less for the divide "BDSM" -"vanilla".

After all, then "vanillas" wouldn't cheat any more than us.